The employment of composite scaffolds with a well-organized architecture and multi-scale porosity certainly represents a valuable approach for achieving a tissue engineered construct to reproduce the middle and long-term behaviour of... more
The employment of composite scaffolds with a well-organized architecture and multi-scale porosity
certainly represents a valuable approach for achieving a tissue engineered construct to reproduce the
middle and long-term behaviour of hierarchically complex tissues such as spongy bone. In this paper,
fibre-reinforced composites scaffold for bone tissue engineering applications is described. These are
composed of poly-L-lactide acid (PLLA) fibres embedded in a porous poly(3-caprolactone) matrix, and
were obtained by synergistic use of phase inversion/particulate leaching technique and filament winding
technology. Porosity degree as high as 79.7% was achieved, the bimodal pore size distribution showing
peaks at ca 10 and 200 mm diameter, respectively, accounting for 53.7% and 46.3% of the total porosity. In
vitro degradation was carried out in PBS and SBF without significant degradation of the scaffold after 35
days, while in NaOH solution, a linear increase of weight lost was observed with preferential degradation
of PLLA component. Subsequently, marrow stromal cells (MSC) and human osteoblasts (HOB) reached
a plateau at 3 weeks, while at 5 weeks the number of cells was almost the same. Human marrow stromal
cell and trabecular osteoblasts rapidly proliferate on the scaffold up to 3 weeks, promoting an oriented
migration of bone cells along the fibre arrangement. Moreover, the role of seeded HOB and MSC on
composite degradation mechanism was assessed by demonstrating a more relevant contribution to PLLA
degradation of MSC when compared to HOB. The novel PCL/PLLA composite scaffolds thus showed
promise whenever tuneable porosity, controlled degradability and guided cell–material interaction are
simultaneously requested.
certainly represents a valuable approach for achieving a tissue engineered construct to reproduce the
middle and long-term behaviour of hierarchically complex tissues such as spongy bone. In this paper,
fibre-reinforced composites scaffold for bone tissue engineering applications is described. These are
composed of poly-L-lactide acid (PLLA) fibres embedded in a porous poly(3-caprolactone) matrix, and
were obtained by synergistic use of phase inversion/particulate leaching technique and filament winding
technology. Porosity degree as high as 79.7% was achieved, the bimodal pore size distribution showing
peaks at ca 10 and 200 mm diameter, respectively, accounting for 53.7% and 46.3% of the total porosity. In
vitro degradation was carried out in PBS and SBF without significant degradation of the scaffold after 35
days, while in NaOH solution, a linear increase of weight lost was observed with preferential degradation
of PLLA component. Subsequently, marrow stromal cells (MSC) and human osteoblasts (HOB) reached
a plateau at 3 weeks, while at 5 weeks the number of cells was almost the same. Human marrow stromal
cell and trabecular osteoblasts rapidly proliferate on the scaffold up to 3 weeks, promoting an oriented
migration of bone cells along the fibre arrangement. Moreover, the role of seeded HOB and MSC on
composite degradation mechanism was assessed by demonstrating a more relevant contribution to PLLA
degradation of MSC when compared to HOB. The novel PCL/PLLA composite scaffolds thus showed
promise whenever tuneable porosity, controlled degradability and guided cell–material interaction are
simultaneously requested.
Research Interests:
In this study, the design and fabrication of porous scaffolds, made of blends of polylactic-co-caprolactone (PLC) and polylactic acid (PLA) polymers, for tissue engineering applications is reported. The scaffolds are prepared by means of... more
In this study, the design and fabrication of porous scaffolds, made of blends of polylactic-co-caprolactone (PLC) and polylactic acid (PLA) polymers, for tissue engineering applications is reported. The scaffolds are prepared by means of a bio-safe thermally induced phase separation (TIPS) approach with or without the addition of NaCl particles used as particulate porogen. The scaffolds are characterized to assess their crystalline structure, morphology and mechanical properties, and the texture of the pores and the pore size distribution. Moreover, in vitro human mesenchymal stem cells (hMSCs) culture tests have been carried out to demonstrate the biocompatibility of the scaffolds. The results of this study demonstrate that all of the scaffold materials processed by means of TIPS process are semi-crystalline. Furthermore, the blend composition affected polymer crystallization and, in turn, the nano and macro-structural properties of the scaffolds. Indeed, neat PLC and neat PLA crystallize into globular and randomly arranged sub micro-size scale fibrous conformations, respectively. Concomitantly, the addition of NaCl particles during the fabrication route allows for the creation of an interconnected network of large pores inside the primary structure while resulted in a significant decrease of scaffolds mechanical response. Finally, the results of cell culture tests demonstrate that both the micro and macro-structure of the scaffold affect the in vitro hMSCs adhesion and proliferation.
In the last decade, bicomponent fibers have been proposed to fabricate bio-inspired systems for tissue repair, regenerative medicine, medical healthcare and clinical applications. In comparison with monocomponent fibers, key advantage... more
In the last decade, bicomponent fibers have been proposed to fabricate bio-inspired systems for tissue repair, regenerative medicine, medical healthcare and clinical applications. In comparison with monocomponent fibers, key advantage concerns their ability of self-adapting to the physiological conditions through an extended pattern of signals - morphological, chemical and physical ones - confined at the single fiber level. Hydrophobic/hydrophilic phases may be variously organized by tuneable processing modes (i.e., blending, core/shell, interweaving) thus offering different benefits in terms of biological activity, fluid sorption and molecular transport properties (first generation). The possibility to efficiently graft cell-adhesive proteins and peptide sequences onto the fiber surface mediated by spacers or impregnating hydrogels allows to trigger cell late activities by a controlled and sustained release in vitro of specific biomolecules (i.e., morphogens, growth factors). Here, we introduce an overview of current approaches based on bicomponent fiber use as extra cellular matrix analogs with cell-instructive functions and hierarchal organization of living tissues.
Research Interests:
The design of functionalized polymers that can elicit specific biological responses and the development of methods to fabricate new devices that incorporate biological cues are of great interest to the biomedical community. The... more
The design of functionalized polymers that can elicit specific biological responses and the development of methods to fabricate new devices that incorporate biological cues are of great interest to the biomedical community. The realization of nanostructured matrices that exhibit biological properties and that comprise fibers with diameters of similar scale to those of the natural extracellular matrix (ECM) would enable the provision of tailored materials for tissue engineering. Accordingly, the goal of this work is to create a biologically active functionalized electrospun matrix capable of guiding neurite growth for the regeneration of nerve tissue. In this study, nanoscale electrospun membranes made of poly ε-caprolactone enhanced with gelatin from calf skin were investigated to validate their biological response under in vitro culture of PC-12 nerve cells. Preliminary observations from SEM studies supported by image analysis highlighted the nanoscale texture of the scaffold with fiber diameters equal to 0.548 ± 0.140 μm. In addition, contact angle measurements confirmed the hydrophilic behavior of the membranes, ascribable to the gelatin content. We demonstrate that the balance of morphological and biochemical properties improves all the fundamental biological events of nerve regeneration, enhancing cell adhesion, proliferation, and differentiation in comparison with PCL nanofibrous scaffolds, as well as supporting the neurite outgrowth.
Research Interests: Engineering, Tissue Engineering, Manufacturing, Cell Adhesion, Morphology, and 22 moreNanocomposites, Electrospinning, Cytotoxicity, Polymer Blends, Biological Sciences, Cell Differentiation, Animals, Wettability, Fabrication, Framework, Gelatin, Membrane, Nerve Regeneration, CHEMICAL SCIENCES, Cattle, Biomaterial, Rats, Cell Proliferation, Polyesters, Biocompatible Materials, Cell Survival, and Biomacromolecules(Nanocomposites, Electrospinning, Cytotoxicity, Polymer Blends, Biological Sciences, Cell Differentiation, Animals, Wettability, Fabrication, Framework, Gelatin, Membrane, Nerve Regeneration, CHEMICAL SCIENCES, Cattle, Biomaterial, Rats, Cell Proliferation, Polyesters, Biocompatible Materials, Cell Survival, and Biomacromolecules)
(Nanocomposites, Electrospinning, Cytotoxicity, Polymer Blends, Biological Sciences, Cell Differentiation, Animals, Wettability, Fabrication, Framework, Gelatin, Membrane, Nerve Regeneration, CHEMICAL SCIENCES, Cattle, Biomaterial, Rats, Cell Proliferation, Polyesters, Biocompatible Materials, Cell Survival, and Biomacromolecules)
Biological studies indicate that numerous materials present in living tissues owe their success to an optimal combination of properties and adaptive structures, rather than to extreme properties per se. Through studying natural tissues... more
Biological studies indicate that numerous materials present in living tissues owe their success to an optimal combination of properties and adaptive structures, rather than to extreme properties per se. Through studying natural tissues and by biomimesis, new polymer and composite materials may be designed to emulate the structural and functional responses of bone. These materials must ensure biochemical affinity with host tissue through judicious mixing of specific chemical cues. Also, they must mimic the response under load exhibited by natural bone through complex organisation of material phases, i.e. embedding of collagen fibres in the extracellular substance. Fibre and particulate reinforced polymers are increasingly significant in the development of new biomedical materials, since they can be engineered more accurately than monolithic structures. Meanwhile, design of nanocomposites with specific morphological and chemical signals is emerging as a powerful approach to the mimesi...
Research Interests:
ABSTRACT Electrohydrodynamics—i.e. electrospinning, electrospraying and atomization—are gaining a growing interest in drug delivery applications, because of a large number of advantages including improved therapeutic index, localized... more
ABSTRACT Electrohydrodynamics—i.e. electrospinning, electrospraying and atomization—are gaining a growing interest in drug delivery applications, because of a large number of advantages including improved therapeutic index, localized delivery/targeting and controlled drugs toxicity level. In the past, microstructured platforms fabricated by the assembly of electrospun fibers have demonstrated to exhibit interesting features as bioactive carriers including extended surface area and high molecular permeability because of fully interconnected pore architecture, thus making the opportunity to incorporate a wide range of actives/drugs for different use. In these systems, molecular release occurs via various molecular transport pathways namely diffusion, desorption and scaffold degradation which may be tuned through a careful control of fiber morphology and composition. However, several shortcomings still concern the possibility to incorporate bioactive species, not exposing molecules to fast and/or uncontrolled denaturation, thus preserving biochemical and biological fiber functionalities. In this context, additive electro spraying (AES)—i.e. integration of electrosprayed nanoparticles into electrospun fiber network—is emerging as interesting route to control “separately” release and functional properties of the scaffolds in order to support cell activities by independent cues, during the tissue formation. Here, we describe the current advances on the use of electrospraying and/or electrospinning until more innovative integrated AES approaches to design molecularly loaded platforms able to spatially and timely release active molecules for different use in tissue engineering and molecular targeting. Copyright © 2015 John Wiley & Sons, Ltd.
Research Interests:
Hydrogels have been successfully used in several biomedical applications, such as controlled drug release and micro-patterning. More recently, the ability to engineer composite hydrogels has generated new opportunities in addressing... more
Hydrogels have been successfully used in several biomedical applications, such as controlled drug release and micro-patterning. More recently, the ability to engineer composite hydrogels has generated new opportunities in addressing challenges in tissue engineering as well as in tissue function restoration via prostheses. Indeed, the knowledge of biocompatible materials and preparation technologies may be efficaciously used in synthesizing biocompatible hydrogels
Research Interests:
Scaffold design plays a pivotal role in tissue engineering and regenerative medicine approaches for creating biological alternatives for implants. The crucial aspect in scaffold design consists of the development of highly porous... more
Scaffold design plays a pivotal role in tissue engineering and regenerative medicine approaches for creating biological alternatives for implants. The crucial aspect in scaffold design consists of the development of highly porous scaffolds, with strict control of porosity features (porosity degree and pore sizes), continuing to provide an adequate mechanical response, mainly in compressive loading, both in vitro and in vivo conditions. A study was undertaken of three-dimensional (3D) porous scaffolds obtained from poly epsilon-caprolactone solution through the phase inversion/salt leaching technique. In particular, the influence of structural porosity features on mechanical response was investigated to establish the correlation between structural parameters and compressive response. Scaffold porosity features can be controlled by changing the amount and size of the porogen agent used. Mechanical response in compression is consistent with porosity features: elastic modulus calculated...
Unidirectional freezing followed by freeze-drying is a way to produce microcellular material from a polymer solution for biomedical application. As a distinctive feature of this type of process, bundles of channels are observed with an... more
Unidirectional freezing followed by freeze-drying is a way to produce microcellular material from a polymer solution for biomedical application. As a distinctive feature of this type of process, bundles of channels are observed with an average diameter of hundreds of microns. Variations in porous morphology, particularly in porosity, density, and degree of regularity of spatial organization of pores, have been observed when polymer concentrations and quenching temperature are changed. To examine these issues in more detail the thermally induced phase separation of a polycaprolactone/dioxane solution was studied as a function of polymer concentration and quenching temperature in connection with the ultimate morphology of the micro-cellular material. We prepared microcellular samples of polycaprolactone by freeze/freeze-drying technique. The microstructure of the material was observed by scanning electron microscopy. Moreover, a mathematical model for the prediction of the temperature profile and morphology was developed. A microstructural disorder region inside the samples was sometimes observed in connection with process parameters. The developed model is able to capture the formation of such a microstructural disorder region as a direct consequence of the slowing down of the solid-liquid interface. Predictions of the model as a function of freezing rate and concentration are in excellent agreement with experimental observation.
Research Interests:
ABSTRACT Hydrogels currently represent a powerful solution to promote the regeneration of soft and hard tissues. Primarily, they assure efficient bio-molecular interactions with cells, also regulating their basic functions, guiding the... more
ABSTRACT Hydrogels currently represent a powerful solution to promote the regeneration of soft and hard tissues. Primarily, they assure efficient bio-molecular interactions with cells, also regulating their basic functions, guiding the spatially and temporally complex multi-cellular processes of tissue formation, and ultimately facilitating the restoration of structure and function of damaged or dysfunctional tissues. In order to overcome basic drawbacks of traditional synthesized hydrogels, many recent strategies have been implemented to realize multi-component hydrogels based on natural and/or synthetic materials with tailored chemistries and different degradation kinetics. Here, a critical review of main strategies has been proposed based on the use of hydrogels-based devices for the regeneration of complex tissues, i.e., osteo-chondral tissues and intervertebral disc.
Research Interests: Polymers()
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This study aimed to produce polycaprolactone (PCL) and PCL/gelatin fibrous scaffolds by electrospinning to engineer functional bone by the careful reproduction of the native microenviroment of the natural tissue. Polymer solutions were... more
This study aimed to produce polycaprolactone (PCL) and PCL/gelatin fibrous scaffolds by electrospinning to engineer functional bone by the careful reproduction of the native microenviroment of the natural tissue. Polymer solutions were processed by electrospinning technique to fabricate 2D and 3D platforms in the form of random flat membranes and bilayered conduits, through the use of collectors - i.e., grounded metal plates and a rotating mandrel, via a 2-step electrospinning process, to produce a bilayered structure. The results showed that solvent properties and the integration of gelatin could strongly influence the scaffold features in terms of fiber size scale and homogeneity, thus potentially affecting the final biological response. Moreover, 3D bilayered devices ensured the mechanical stability required to guide the forming bone during the regeneration process. Overall, bioactive 2D or 3D electrospun platforms with microstructured and nanostructured properties can be used successfully as extracellular matrix analogues in bone regeneration.
Research Interests:
Only recently polymers with intrinsic conductive properties have been studied in relation to their incorporation into bioactive scaffolds for use in tissue engineering. The reason for this interest is that such scaffolds could... more
Only recently polymers with intrinsic conductive properties have been studied in relation to their incorporation into bioactive scaffolds for use in tissue engineering. The reason for this interest is that such scaffolds could electrically stimulate cells and thus regulate specific cellular activities, and by this means influence the process of regeneration of those tissues that respond to electrical impulses. In our work, macroporous hydrogels are developed with controlled pore morphology and conductive properties to enable sufficient cell signaling to supply events inherent to nerve regeneration. A hybrid material has been prepared by in situ precipitation of polyaniline (PANi) in polyethyleneglycol diacrylate (PEGDA) solution, followed by crosslinking via UV irradiation. A porous architecture, characterized by macropores from 136 μm to 158 μm in size, has been achieved by sodium chloride particle leaching. In this work, we demonstrate that PANi synthesis and hydrogel crosslinking combine to enable the design of materials with suitable conductive behaviour. The presence of PANi evidently increased the electrical conductivity of the hybrid material from (1.1 ± 0.5) × 10(-3) mS/cm with a PANi content of 3wt%. The hydrophilic nature of PANi also enhanced water retention/proton conductivity by more than one order of magnitude. In vitro studies confirmed that 3 wt% PANi also improve the biological response of PC12 and hMSC cells. Hybrid PANi/PEGDA macroporous hydrogels supplement new functionalities in terms of morphological and conductive properties, both of which are essential prerequisites to drive nerve cells in regenerative processes.
Research Interests:
Research Interests:
Biodegradable microparticles and nanoparticles are receiving increased attention for their ability to serve as a viable carrier for site-specific delivery of genes, drugs and other biomolecules. Electrospraying represents a challenging... more
Biodegradable microparticles and nanoparticles are receiving increased attention for their ability to serve as a viable carrier for site-specific delivery of genes, drugs and other biomolecules. Electrospraying represents a challenging technology which allows for the preparation of biodegradable particles with high bioavailability, good encapsulation, controlled release and fewer toxic properties. Chitosan and polycaprolactone (PCL) particles were processed via electrospraying with control of basic process parameters: voltage and flow rate. PCL microparticles with spherical shape or flattened particles were obtained as a function of the concentration of the processed solutions, which affects evaporation and chain entanglement formation. Chitosan nanoparticles with submicrometric sizes were obtained by carefully adjusting voltage and flow rate, which enables the control of particle size and distribution. We evaluated the benefits of the electrospraying technique to control the morphology of biodegradable microparticles and nanoparticles for drug-delivery applications. The implementation of simple technological solutions which combine the use of standard electrospraying and electrospinning by simultaneous or sequential steps, opens the way toward the development of new, interesting devices for drug-delivery applications such as tumor targeting and oral delivery.
Research Interests:
Research Interests: Scaffold()
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Human mesenchymal stem cells (hMSC) currently represent a major cell resource in the research laboratory, to study differentiated-cell behavior in 3D scaffolds during the regeneration processes. Adhesion and differentiation of stem cells... more
Human mesenchymal stem cells (hMSC) currently represent a major cell resource in the research laboratory, to study differentiated-cell behavior in 3D scaffolds during the regeneration processes. Adhesion and differentiation of stem cells to a specific phenotype are achieved by culturing them in apposite culture media under precise conditions. Meanwhile, hydrolytic degradation of polymeric scaffolds allows implanted cells to synthesize their own extracellular matrix in situ after implantation so that the degeneration of the foreign scaffold is temporally matched by creation of the new innate one. In this context, structural properties and biochemical signals may concur to influence the cell response to the environmental stimuli during the culture. So, it becomes mandatory to introduce robust protocols to treat hMSC alone-before the culture-and in combination with the scaffolds for the next investigation by scanning electron microscopy. Here, we describe the protocols used to manage hMSC before and during the culture in order to obtain more detailed information on cell mechanisms mediated by polymeric scaffolds.
Research Interests:
Research Interests:
Research Interests:
ABSTRACT The current landscape of bone regeneration research has focused on novel processing techniques for scaffolds and the employment of nanostructured and bioactive materials to trigger specific cell function in osteogenic way. The... more
ABSTRACT The current landscape of bone regeneration research has focused on novel processing techniques for scaffolds and the employment of nanostructured and bioactive materials to trigger specific cell function in osteogenic way. The investigation of novel technological methods and materials may guide towards more promising and still unexplored strategies to fabricate innovative scaffolds for hard tissue regeneration. Here, we focus on recent advancements in the area of tissue-engineered scaffold fabrication with emphasis on polymer/ceramic composites and micro and/or nanotexturing processes (i.e, electrospinning) as well as their combinations. In particular, different approaches based on the design of bioactive micro/nanonanocomposites, hybrids and nanofibers will be presented with some promise for engineering three-dimensional ECM analogues of bone.
Complex architecture of natural tissues such as nerves requires the use of multifunctional scaffolds with peculiar topological and biochemical signals able to address cell behavior towards specific events at the cellular (microscale) and... more
Complex architecture of natural tissues such as nerves requires the use of multifunctional scaffolds with peculiar topological and biochemical signals able to address cell behavior towards specific events at the cellular (microscale) and macromolecular (nanoscale) level. In this context, the electrospinning technique is useful to generate fiber assemblies having peculiar fiber diameters at the nanoscale and patterned by unidirectional ways, to facilitate neurite extension via contact guidance. Following a bio-mimetic approach, fully aligned polycaprolactone fibers blended with gelatin macromolecules have been fabricated as potential bioactive substrate for nerve regeneration. Morphological and topographic aspects of electrospun fibers assessed by SEM/AFM microscopy supported by image analyses elaboration allow estimating an increase of fully aligned fibers from 5 to 39% as collector rotating rate increases from 1,000 to 3,000 rpm. We verify that fully alignment of fibers positively influences in vitro response of hMSC and PC-12 cells in neurogenic way. Immunostaining images show that the presence of topological defects, i.e., kinks--due to more frequent fiber crossing--in the case of randomly organized fiber assembly concurs to interfere with proper neurite outgrowth. On the contrary, fully aligned fibers without kinks offer a more efficient contact guidance to direct the orientation of nerve cells along the fibers respect to randomly organized ones, promoting a high elongation of neurites at 7 days and the formation of bipolar extensions. So, this confirms that the topological cue of fully alignment of fibers elicits a favorable environment for nerve regeneration.
Research Interests:
Drug delivery applications using biodegradable polymeric microspheres are becoming an important means of delivering therapeutic agents. The aim of this work was to modulate the microporosity of poly(epsilon-caprolactone) (PCL)... more
Drug delivery applications using biodegradable polymeric microspheres are becoming an important means of delivering therapeutic agents. The aim of this work was to modulate the microporosity of poly(epsilon-caprolactone) (PCL) microcarriers to control protein loading capability and release profile. PCL microparticles loaded with BSA (bovine serum albumin) have been de novo synthesized with double emulsion solvent evaporation technique transferred and adapted for different polymer concentrations (1.7 and 3% w/v) and stabilizer present in the inner aqueous phase (0.05, 0.5 and 1% w/v). SEM (scanning electron microscope) and CLSM (confocal laser scanning microscope) analysis map the drug distribution in homogeneously distributed cavities inside the microspheres with dimensions that can be modulated by varying double emulsion process parameters. The inner structure of BSA-loaded microspheres is greatly affected by the surfactant concentration in the internal aqueous phase, while a slight influence of polymer concentration in the oil phase was observed. The surfactant concentration mainly determines microspheres morphology, as well as drug release kinetics, as confirmed by our in-vitro BSA release study. Moreover, the entrapped protein remained unaltered during the protein encapsulation process, retaining its bio-activity and structure, as shown through a dedicated gel chromatographic analytical method.
Research Interests: Materials Engineering, Biomedical Engineering, Kinetics, Materials, Scanning Electron Microscopy, and 18 moreDrug delivery, Animals, Laser Scanning, Drug Delivery Systems, Spectrophotometry, Proteins, Cattle, Analytical Method, Particle Size, Scanning Electron Microscope, Emulsions, Surface Active Agents, Microspheres, Bovine Serum Albumin, Polyesters, Process Parameters, Drug Carriers, and Drug Release
Research Interests:
Research Interests:
The implementation of bio-inspired strategies in developing scaffolds for the reconstruction of oral, craniofacial and bone skeletal tissues after injury or resection remains a challenge. Currently, advanced scaffolds comprising... more
The implementation of bio-inspired strategies in developing scaffolds for the reconstruction of oral, craniofacial and bone skeletal tissues after injury or resection remains a challenge. Currently, advanced scaffolds comprising nanofibers endowed with biochemical/biophysical signaling capability offer great advantages in bone regeneration, because of their faithful mimesis of the characteristic size scales encountered in the fibrous network of the native extracellular matrix (ECM). In this study, we investigate the biological potential of nanofibers made of polycaprolactone and gelatin on guiding the regenerative mechanisms of bone. Contact angle measurements and environmental SEM investigations indicate a weak linkage of gelatin molecules to PCL chains, facilitating an efficient adhesion signal to cells up to 3 days of culture. In vitro studies performed on human mesenchymal stem cells (hMSC) until 3 weeks in culture medium with osteogenic supplementation, clearly showing the effectiveness of PCL/Gelatin electrospun scaffolds in promoting bone osteogenesis and mineralization. The increase of alkaline phosphatase activity (ALP) and gene expression of bone-related molecules (bone sialoprotein, osteopontin and osteocalcin), indicated by immunodetection and upregulation level of mRNA, confirm that proposed nanofibers promote the osteogenic differentiation of hMSC, preferentially in osteogenic medium. Moreover, the evidence of newly formed collagen fibers synthesis by SIRCOL and their mineralization evaluated by Alizarin Red staining and EDS mapping of the elements Ca, P and Mg corroborate the idea that native osteoid matrix is ultimately deposited. All these data suggest that PCL and gelatin electrospun nanofibers have great potential as osteogenesis promoting scaffolds for successful application in bone surgery.
Research Interests:
Research Interests: Materials Engineering, Chemical Engineering, Tissue Engineering, Regeneration, Biomimetics, and 13 moreScanning Electron Microscopy, Extracellular Matrix, Porosity, Animals, Fluorescent Antibody Technique, Achilles tendon, Cell Proliferation, Rabbits, Polyesters, Tensile Strength, Ligaments, Mechanical Processes, and Biomechanical Phenomena
The use of scaffold-aided strategies for the regeneration of biological tissues requires the fulfilment of an accurate architectural design, that is, micro and macrostructure, with the final goal of realizing architectures to adopt as... more
The use of scaffold-aided strategies for the regeneration of biological tissues requires the fulfilment of an accurate architectural design, that is, micro and macrostructure, with the final goal of realizing architectures to adopt as guidance for those cell activities specific to the formation of novel tissues. Here, highly porous scaffolds made up of biodegradable poly(ε-caprolactone) (PCL) have been realized by thermally induced phase separation (TIPS). Two different polymer/solvent systems, derived by the dissolution of PCL in dioxane and DMSO respectively, were investigated. The aim was to demonstrate the high potential of TIPS technique, in imprinting specific pore features to the polymer matrices, by a conscious selection of polymer/solvent systems. The investigation of pore architecture by SEM/mercury intrusion porosimetry/image analyses, firstly allow to detect remarkable variations in porosity (from 92% to 78%,) and pore sizes, ranging from micro-scale (ca 10 µm) to macro-scale (greater than 100 µm) as a function of the used polymer/solvent systems. Moreover, experimental and theoretical evidences referred to scaffold shaped in custom-made molds--a thin Teflon ring between two copper plates--allow exploring how the sensitivity of polymer solution features (i.e., crystallinity, thermal inertia) to the cooling temperature can affect the alignment of polymer phases and, ultimately, scaffold pore anisotropy. Analytical results supported by preliminary biological studies demonstrate the higher ability of PCL/dioxane solution to promote the formation of aligned pores which provide a morphological guidance to cell advance during the preliminary stage of culture. These findings, taken as a whole, put the basis for a better informed regeneration of structurally complex tissues based on the modeling of scaffold micro and macro-architecture by thermodynamic forces.
Research Interests:
Polycaprolactone (PCL) and PCL/gelatin membranes and films were fabricated by electrospinning and solvent casting. A systematic analysis of the morphology evolution, as degradation occurred, was made to separate the contribution of fiber... more
Polycaprolactone (PCL) and PCL/gelatin membranes and films were fabricated by electrospinning and solvent casting. A systematic analysis of the morphology evolution, as degradation occurred, was made to separate the contribution of fiber nanotexture and gelatin biochemical signal on cell adhesion and proliferation. Field emission scanning electron microscope was used to assess the contribution of platform architecture on the gelatin degradation
Research Interests:
Bone and ligament injuries present the greatest challenges in connective tissue regeneration. The design of materials for these applications lies at the forefront of material science and is the epitome of its current ambition. Indeed, its... more
Bone and ligament injuries present the greatest challenges in connective tissue regeneration. The design of materials for these applications lies at the forefront of material science and is the epitome of its current ambition. Indeed, its goal is to design and fabricate reproducible, bioactive and bioresorbable 3D scaffolds with tailored properties that are able to maintain their structure and integrity for predictable times, even under load-bearing conditions. Unfortunately, the mechanical properties of today's available porous scaffolds fall short of those exhibited by complex human tissues, such as bone and ligament. The manipulation of structural parameters in the design of scaffolds and their bioactivation, through the incorporation of soluble and insoluble signals capable of promoting cell activities, are discussed as possible strategies to improve the formation of new tissues both in vitro and in vivo. This review focuses on the different approaches adopted to develop bioactive composite systems for use as temporary scaffolds for bone and anterior ligament regeneration.
Research Interests:
Research Interests:
The traditional paradigm of tissue engineering of regenerating in vitro tissue or organs, through the combination of an artificial matrix and a cellular population has progressively changed direction. The most recent concept is the... more
The traditional paradigm of tissue engineering of regenerating in vitro tissue or organs, through the combination of an artificial matrix and a cellular population has progressively changed direction. The most recent concept is the realization of a fully functional biohybrid, where both, the artificial and the biotic phase, concur in the formation of the novel organic matter. In this direction, interest is growing in approaches taking advantage of the control at micro- and nano-scale of cell material interaction based on the realization of elementary tassels of cells and materials which constitute the beginning point for the expansion of 3D more complex structures. Since a spontaneous assembly of all these components is expected, however, it becomes more fundamental than ever to define the features influencing cellular behavior, either they were material functional properties, or material architecture. In this work, it has been investigated the direct effect of electrospun fiber sizes on oxygen metabolism of h-MSC cells, when any other culture parameter was kept constant. To this aim, thin PCL electrospun membranes, with micro- and nano-scale texturing, were layered between two collagen slices up to create a sandwich structure (µC-PCL-C and nC-PCL-C). Cells were seeded on membranes, and the oxygen consumption was determined by a phosphorescence quenching technique. Results indicate a strong effect of the architecture of scaffolds on cell metabolism, also revealed by the increasing of HIF1-α gene expression in nC-PCL-C. These findings offer new insights into the role of materials in specific cell activities, also implying the existence of very interesting criteria for the control of tissue growth through the tuning of scaffold architecture.