Cellular Scaffolds Research Articles

Optogenetics Reveals Roles for Supporting Cells in Force Transmission to and From Outer Hair Cells in the Mouse Cochlea.

Outer hair cells (OHCs) of the organ of Corti (OoC), acting as bidirectional cellular mechanoelectrical transducers, generate, receive, and exchange forces with other major elements of the cochlear partition, including the sensory inner hair cells (IHCs). Force exchange is mediated via a supporting cell scaffold, including Deiters' (DC) and outer pillar cells (OPC), to enable the sensitivity and exquisite frequency selectivity of the mammalian cochlea and to transmit its responses to the auditory nerve. To selectively activate DCs and OPCs in male and female mice, we conditionally expressed in them a hyperpolarizing halorhodopsin (HOP), a light-gated inward chloride ion pump, and measured extracellular receptor potentials (ERPs) and their DC component (ERPDCs) from the cortilymph, which fills the OoC fluid spaces, and compared the responses with similar potentials from HOP-/- littermates. The compound action potentials (CAP) of the auditory nerve were measured as an indication of IHC activity and transmission of cochlear responses to the CNS. HOP light-activated hyperpolarization of DCs and OPCs suppressed cochlear amplification through changing the timing of its feedback, altered basilar membrane (BM) responses to tones at all measured levels and frequencies, and reduced IHC excitation. HOP activation findings reported here complement recent studies that revealed channelrhodopsin activation depolarized DCs and OPCs and effectively bypassed, rather than blocked, the control of OHC mechanical and electrical responses to sound and their contribution to timed and directed electromechanical feedback to the mammalian cochlea. Moreover, our findings identify DCs and OPCs as potential targets for the treatment of noise-induced hearing loss.

Diels-Alder Photoclick Patterning of Extracellular Matrix for Spatially Controlled Cell Behaviors.

Strategies that mimic the spatial complexity of natural tissues can provide cellular scaffolds to probe fundamental questions in cell biology and offer new materials for regenerative medicine. Here, the authors demonstrate a light-guided patterning platform that uses natural engineered extracellular matrix (ECM) proteins as a substrate to program cellular behaviors. A photocaged diene which undergoes Diels-Alder-based click chemistry upon uncaging with 365nm light is utilized. By interfacing with commercially available maleimide dienophiles, patterning of common ECM proteins (collagen, fibronectin Matrigel, laminin) with readily purchased functional small molecules and growth factors is achieved. Finally, the use of this platform to spatially control ERK activity and migration in mammalian cells is highlighted, demonstrating programmable cell behavior through patterned chemical modification of natural ECM.

3D bioprinted pectin-based hydrogel as sustainable biomaterials for musculoskeletal tissue engineering

Development of sustainable biomaterials are rapidly emerging as alternatives to fossil-based products. The new generation of eco-friendly “green” biomaterials manufactured using the latest advanced technologies in tissue engineering offers new possibilities for biomedical field in terms of drug delivery, therapeutics and damaged tissues repair.Musculoskeletal tissue has limited self-repair capacity, hence, there is an urgent need for effective treatment modalities to repair and prevent progression to chronic disease. More recently, cellular scaffolds are being considered as new therapeutic approaches for tissue engineering and 3D bioprinting tissues. Despite the success of using bioprinting techniques to create hierarchical constructs with uniformly dispersed cells, there is limited research on “green” bioactive components which can stimulate both osteogenesis and chondrogenesis simultaneously. Based on previous studies; pectin RG-I has been shown to have osteogenic and anti-inflammatory properties. This study focused on the fabrication of a pectin RG-I bioink for the incorporation of chondrocytes. The RG-I was extracted from agricultural side streams from the potato starch. Three different concentrations (0 μg/mL, 500 μg/mL, 700 μg/mL) of RG-I were evaluated. Human chondrocytes were incorporated within the bioinks and 3D bioprinted to create viable scaffolds. Physical properties were characterized by swelling and degradation studies. Cell response was assessed with proliferation, cell viability and morphology, and gene expression of galectin-3, collagen type-l, and collagen type- ll. All three groups of bioinks showed water intake and degradation ability as well as ideal printability and shape fidelity. Bioprinting did not cause any detrimental effect on cell-laden ink and cells were observed to be homogeneously dispersed. The formulation of 500 μg/mL pectin RG-I bioink showed the most promising properties for potential use to repair osteochondral defects due to its anti-inflammatory effect and fibrosis inhibition. The use of RG-I opens possibilities to manufacture multifunctional sustainable “green” biomaterials.

Effect of tetracycline hydrochloride application on dental pulp stem cell metabolism-booster or obstacle for tissue engineering?

Introduction: Stem cells and scaffolds are an important foundation and starting point for tissue engineering. Human dental pulp stem cells (DPSC) are mesenchymal stem cells with self-renewal and multi-directional differentiation potential, and are ideal candidates for tissue engineering due to their excellent biological properties and accessibility without causing major trauma at the donor site. Tetracycline hydrochloride (TCH), a broad-spectrum antibiotic, has been widely used in recent years for the synthesis of cellular scaffolds to reduce the incidence of postoperative infections. Methods: In order to evaluate the effects of TCH on DPSC, the metabolism of DPSC in different concentrations of TCH environment was tested. Moreover, cell morphology, survival rates, proliferation rates, cell migration rates and differentiation abilities of DPSC at TCH concentrations of 0-500μg/ml were measured. Phalloidin staining, live-dead staining, MTS assay, cell scratch assay and real-time PCR techniques were used to detect the changes in DPSC under varies TCH concentrations. Results: At TCH concentrations higher than 250μg/ml, DPSC cells were sequestered, the proportion of dead cells increased, and the cell proliferation capacity and cell migration capacity decreased. The osteogenic and adipogenic differentiation abilities of DPSC, however, were already inhibited at TCH con-centrations higher than 50μg/ml. Here, the expression of the osteogenic genes, runt-related transcription factor 2 (RUNX2) and osteocalcin (OCN), the lipogenic genes lipase (LPL), as well as the peroxisome proliferator-activated receptor-γ (PPAR-γ) expression were found to be down-regulated. Discussion: The results of the study indicated that TCH in concentrations above 50µg/ml negatively affects the differentiation capability of DPSC. In addition, TCH at concentrations above 250µg/ml adversely affects the growth status, percentage of living cells, proliferation and migration ability of cells.

253. ESOPHAGEAL REGENERATION FOLLOWING IMPLANTATION OF A TISSUE ENGINEERED ESOPHAGEAL IMPLANT: UNDERSTANDING THE REGENERATION TIME COURSE AND TRANSLATION TO THE CLINIC

Abstract Diseases of the esophagus, damage of the esophagus due to injury or congenital defects during fetal esophageal development, i.e., Esophageal Atresia (EA), typically require surgical intervention to restore esophageal continuity. The development of novel tissue engineered tubular structures would improve the treatment options for these conditions by providing an alternative that is organ sparing and can be manufactured to fit the exact dimensions of the defect. Biostage has developed an autologous tissue engineered Esophageal Implant, composed of an electrospun cellular scaffold seeded with autologous mesenchymal stromal cells, that can stimulate repair and regeneration of segmental defects in the esophagus following surgical implantation. Biostage has received approval from the FDA on an Investigational New Drg (IND) application for a clinical trial in adults requiring esophageal reconstruction. A discussion of the regeneration time course, in adults and in a pediatric model as well as the critical features of the IND, the Regulatory process for treating adults with the intention to treat Esophageal Atresia and the clinical study parameters highlight the novelty of this tissue engineered combination product.

Adipose Mesenchymal Stem Cell Derived Exosomes Promote Keratinocytes and Fibroblasts Embedded in Collagen/Platelet-Rich Plasma Scaffold and Accelerate Wound Healing.

Engineered skin substitutes derived from human skin significantly reduce inflammatory reactions mediated by foreign/artificial materials and are consequently easier to use for clinical application. Type I collagen is a main component of the extracellular matrix during wound healing and has excellent biocompatibility, and platelet-rich plasma can be used as the initiator of the healing cascade. Adipose mesenchymal stem cell derived exosomes are crucial for tissue repair and play key roles in enhancing cell regeneration, promoting angiogenesis, regulating inflammation, and remodeling extracellular matrix. Herein, Type I collagen and platelet-rich plasma, which provide natural supports for keratinocyte and fibroblast adhesion, migration, and proliferation, are mixed to form a stable 3D scaffold. Adipose mesenchymal stem cell derived exosomes are added to the scaffold to improve the performance of the engineered skin. The physicochemical properties of this cellular scaffold are analyzed, and the repair effect is evaluated in a full-thickness skin defect mouse model. The cellular scaffold reduces the level of inflammation and promotes cell proliferation and angiogenesis to accelerate wound healing. Proteomic analysis shows that exosomes exhibit excellent anti-inflammatory and proangiogenic effects in collagen/platelet-rich plasma scaffolds. The proposed method provides a new therapeutic strategy and theoretical basis for tissue regeneration and wound repair.

Electrospun Scaffolds for Tissue Engineering: A Review

Tissue engineering and regenerative medicine have emerged as innovative approaches to enhance clinical outcomes by addressing tissue lesions and degenerations that can significantly impair organ function. Since human tissues have limited regenerative capacity, the field of regenerative medicine aims to restore damaged tissues and their functionalities. Recent decades have witnessed remarkable progress in materials science, tissue engineering, and medicine, leading to the development of regenerative engineering. This interdisciplinary field has revolutionized the production of artificial matrices, enabling the design of anatomically accurate structures with enhanced biocompatibility, bioabsorption, and cell adhesion. Among the techniques utilized for fabricating cellular scaffolds, the electrospinning of fibers stands out as an ideal approach due to its ability to mimic the characteristics of the extracellular matrix (ECM). Electrospun scaffolds exhibit distinct advantages, including a high surface area-to-volume ratio, exceptional porosity, uniformity, compositional diversity, structural flexibility, and the ease of functionalization with bioactive molecules for controlled release. These versatile properties allow for the creation of nanofiber scaffolds that closely resemble the architecture of the ECM. Consequently, they facilitate the transport of nutrients and oxygen to cells as well as the incorporation of growth factors to stimulate cell growth. These advancements open up a wide range of applications in the field of regenerative medicine.

The effect of eliminating sintering during the synthesis of 3D scaffolds using the gel-casting method on their biological characteristics: in vivo and in vitro evaluations

The possibility of making shapeable three-dimensional scaffolds along with suitable mechanical properties is one of the most challenging points in tissue engineering. This study investigated the effect of the eliminating sintering during the synthesis of Hydroxyapatite/Agarose nanocomposite foam produced by gel-casting method, as bone tissue cellular scaffold, on its biological characteristics. The Hydroxyapatite/Agarose nanocomposite foam was synthesized by gel-casting, and samples were divided into two groups: group S, in which half of the samples were sintered, and group C, which the other half of the samples were left unsintered. To assess in vitro cytotoxicity, the supernatant culture medium was extracted from 100 mg ml−1 foam suspension in complete culture medium after 72 h incubation and diluted into various concentrations. SaOs-II cells were incubated with extracts of each scaffold at different concentrations and analyzed using the MTT assay. Additionally, in vivo characteristics were evaluated by implanting the scaffolds in rat tibia. Overall, the number of living cells was higher in group S than in group C, except for concentrations of 25% and 75% after 24 and 48 h of incubation, respectively. MTT assay results indicated that concentrations below 50% for group S and 25% for group C could be considered non-toxic. All in vivo variables exhibited significant changes over time, with most changes occurring faster in group S than in group C. There was a statistically significant difference between the two groups in terms of inflammation rate, osteocyte, osteoblast, and osteoclast count, as well as remaining biomaterial percentage only on day 30. Despite the delay in the tissue regeneration process observed by eliminating sintering during the gel-casting method, it is recommended as a means of producing reversible polymeric scaffolds with proper handling, cutting, and shaping capabilities that can be easily applied by clinicians during surgery according to the specific defect site.

A Workflow to Produce a Low-Cost In Vitro Platform for the Electric-Field Pacing of Cellularised 3D Porous Scaffolds.

Endogenous electrically mediated signaling is a key feature of most native tissues, the most notable examples being the nervous and the cardiac systems. Biomedical engineering often aims to harness and drive such activity in vitro, in bioreactors to study cell disease and differentiation, and often in three-dimensional (3D) formats with the help of biomaterials, with most of these approaches adopting scaffold-free self-assembling strategies to create 3D tissues. In essence, this is the casting of gels which self-assemble in response to factors such as temperature or pH and have capacity to harbor cells during this process without imparting toxicity. However, the use of materials that do not self-assemble but can support 3D encapsulation of cells (such as porous scaffolds) warrants consideration given the larger repertoire this would provide in terms of material physicochemical properties and microstructure. In this method and protocol paper, we detail and provide design codes and assembly instructions to cheaply create an electrical pacing bioreactor and a Rig for Stimulation of Sponge-like Scaffolds (R3S). This setup has also been engineered to simultaneously perform live optical imaging of the in vitro models. To showcase a pilot exploration of material physiochemistry (in this aspect material conductivity) and microstructure (isotropy versus anisotropy), we adopt isotropic and anisotropic porous scaffolds composed of collagen or poly(3,4-ethylene dioxythiophene):polystyrenesulfonate (PEDOT:PSS) for their contrasting conductivity properties yet similar in porosity and mechanical integrity. Electric field pacing of mouse C3H10 cells on anisotropic porous scaffolds placed in R3S led to increased metabolic activity and enhanced cell alignment. Furthermore, after 7 days electrical pacing drove C3H10 alignment regardless of material conductivity or anisotropy. This platform and its design, which we have shared, have wide suitability for the study of electrical pacing of cellularized scaffolds in 3D in vitro cultures.

Multi-scale cellular PLA-based bionic scaffold to promote bone regrowth and repair

Large bone defects have presented a significant challenge in orthopedic treatments, and the emergence of tissue-engineered scaffolds has introduced new avenues for treatment. Nonetheless, the clinical application of such scaffolds has been hindered by drawbacks like inadequate mechanical properties, and deficient osteogenesis. Herein, a biocompatible polylactic acid (PLA) based composite was proposed to emulate cancellous bone's morphology by incorporating nano-hydroxyapatite (nHA). In addition, a quantity of Mg2+ and chitosan (CS) as active osteogenic factors were adopted to imitate the bone marrow mesenchymal components in vivo. Using a pre-evaporated solvent and sacrificial multi-template techniques, the cellular PLA-based tissue engineering scaffolds containing macropores larger than 100 μm and micropores smaller than 10 μm were developed. The scaffold's bionic structure, osteogenic active component, and multi-scale cellular make it comparable to cancellous bone, with favorable mechanical properties and hydrophilicity. Vitro tests using Sprague-Dawley (SD) rat bone marrow mesenchymal stem cells (rBMSCs) demonstrated the scaffold's excellent biocompatibility to induce high efficiency of osteogenic differentiation. The bionic porous scaffold with multi-scale cellular structure also can recruit rBMSCs, promote bone regrowth and osteogenic differentiation, and facilitate the regeneration of defective bone tissue for repair. This contribution presented a promising strategy for future advancements in bone tissue engineering.

Smart implants: 4D-printed shape-morphing scaffolds for medical implantation.

Biomedical implants have recently shown excellent application potential in tissue repair and replacement. Applying three-dimensional (3D) printing to implant scaffold fabrication can help to address individual needs more precisely. Fourdimensional (4D) printing emerges rapidly based on the development of shape-responsive materials and design methods, which makes the production of dynamic functional implants possible. Smart implants can be pre-designed to respond to endogenous or exogenous stimuli and perform seamless integration with regular/ irregular tissue defects, defect-luminal organs, or curved structures via programmed shape morphing. At the same time, they offer great advantages in minimally invasive surgery due to the small-to-large volume transition. In addition, 4D-printed cellular scaffolds can generate extracellular matrix (ECM)-mimetic structures that interact with the contacting cells, expanding the possible sources of tissue/organ grafts and substitutes. This review summarizes the typical technologies and materials of 4D-printed scaffolds, and the programming designs and applications of these scaffolds are further highlighted. Finally, we propose the prospects and outlook of 4D-printed shape-morphing implants.

Ultra-short laser structuring of 3D-microfabricated non-resorbable polystyrene polymer to anchor cellular adhesion

Tissue engineering is emerging as a preferred choice for regeneration of irreversible bone tissue defects. It’s main “weapons” are the artificially created biocompatible three-dimensional cellular matrices that mimic the extracellular matrix’s structure and provide a mechanically stable inert substrate for the natural growth of cells. These porous scaffolds provide sufficient inner surface for cell adhesion, migration, proliferation and protrusion “inside” the temporal implant, facilitating in that way the natural bone ingrowth and vascularization. This leads, eventually, to overgrowing the outer and inner surface of the biomimetic implant with recipient self-formed bone tissue, thus avoiding a possible immune response.In the current study 3D Polystyrene (PS) non-resorbable synthetic cellular bone scaffolds, produced by 3D microfabrication technology, were additionally structured by applying femtosecond (fs) laser radiation with variable parameters thus achieving optimal laser processing conditions, for creation of 3D matrix with enhanced fiber surface properties. The main aim is the establishment of surface structured microporous biomimetic scaffolds, providing improved cell adhesion, infiltration and formation of extracellular matrix. The 3D laser functionalized PS samples were investigated by Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray analysis (EDX), confocal (optical profilometer) and roughness analyses for evaluation of their morphological and chemical properties before and after fs structuring was performed. Water contact angle (WCA) evaluation was also conducted. Future experimental work will include in vitro cellular studies for determining the optimal structuring laser parameters, providing osteoconductive and osteoinductive qualities of the 3D fs-microstructured PS scaffolds.

Proliferation kinetics and mineralization properties of MC3T3‐E1 cells on whey protein isolate scaffolds for bone tissue regeneration

AbstractThe purpose of the study is to assess the influence of scaffold composition and properties on the cellular proliferation and scaffold mineralization on a whey protein isolate (WPI) scaffold. Scaffolds of varying concentrations of WPI, calcium chloride, and amylopectin are seeded with cells, and growth curves are constructed from cell density measurements following incubation. Non‐linear regression yields kinetic growth parameters which are compared for quantitative assessment of scaffold performance. Scaffolds show biocompatibility and the ability to sustain a culture for the length of the study. For up to 14 days, the data are well described by exponential growth. Thereafter, saturation behavior appears, and the data fit well to a sigmoidal model. The seeding efficiency improves with increasing WPI concentration, peaking at 5 mM CaCl2, and decreases with added amylopectin. The growth constant is almost independent of scaffold composition, with possible increases with added CaCl2 and amylopectin. The retardation constant is independent of composition. Scaffolds cultured in differentiation and mineralization conditions, shows development of a mineralized matrix both on acellular scaffold surfaces and in osteoblast cultures. The ability of the unmodified WPI gel surfaces to promote the growth and differentiation of a model preosteoblast provides valuable trends and concentration effects for further scaffold design.

A Senomorphic‐Conjugated Scaffold for Application of Senescent Cells in Regenerative Medicine

AbstractProcuring a sufficient amount of cells is essential for cell‐based regenerative therapy. However, the application of senescent cells replicated using cell culture is limited because the cells have lost their regenerative ability or produce deleterious senescence‐associated secretory phenotypes (SASPs). In this study, using a senomorphic (epigallocatechin gallate [EGCG]), which could modulate SASP secretion from senescent cells, nonsenescent and senescent dedifferentiated fat cells from rats (rDFAT cells), and congenital cleft‐jaw defects in rats, the authors show that the senomorphic (EGCG)‐conjugated cellular scaffold restores the bone regenerative ability of senescent multipotent progenitor cells, even in vivo. In this osteogenic process, the EGCG‐conjugated scaffold attenuates the production of representative SASPs (i.e., interleukin [IL]‐6 and tumor necrosis factor‐α) and reactive oxygen species in vivo and in vitro. In polymerase chain reaction arrays in vitro, the EGCG‐conjugated cellular scaffold suppresses the expression of genes associated with deleterious SASP factors for bone formation (e.g., Csf2, IL‐1a, and others) from senescent rDFAT cells and elevates the expression of potential osteogenesis‐ and bone remodeling‐ related gene (e.g., Cxcl13 and Spp1). These results provide insights to expand the application of senomorphics and senescent stem/multipotent progenitor cells in cell‐based regenerative medicine.

Roles of biomaterials in modulating the innate immune response in ocular therapy

The eye is a hard-to-treat organ due to its poor regenerative capacity and susceptibility to inflammation; as a result, it has an immune privilege mechanism. In the case of ocular degenerative disorders, chronic and uncontrolled ocular inflammations can overcome this immune response to initiate and exacerbate tissue degeneration, ultimately leading to blindness. Recent landmark discoveries on the key roles of the ocular innate immune system in regulating acute and chronic inflammations as well as tissue fibrosis and homeostasis have shed light on the value of novel treatment interventions in modulating ocular immune responses at the molecular, cellular, and tissue levels. This strategy can be attained by using therapeutics to target resident phagocytes and antigen-presenting cells, namely, microglia and dendritic cells, as well as infiltrating neutrophils and macrophages. Biomaterials are foreign materials to the host and interact with innate immune cells. To leverage such intrinsic immunomodulatory properties, biomaterials such as implants, injectable depots, and nano/micro particles can be used alone as a treatment or with different payloads as carriers in immune-related ocular disorders. This article discusses how physicochemical properties such as biodegradability, size, shape, and charge affect biomaterials’ interaction with the eye’s innate immune system, therefore influencing outcomes towards pro- or anti-inflammatory responses. Knowledge about the eye’s immunological response is required for designing tolerogenic biomaterials including intraocular lenses, cellular scaffolds, therapeutic molecule depots, or carriers of gene therapies. The discussion presented in this review will shed light on the potential use of biomaterials to direct immune responses toward favorable treatment outcomes.

Three‐dimensional printing of triply periodic minimal surface structured scaffolds for load‐bearing bone defects

AbstractThe porous and cellular architecture of scaffolds plays a significant role in mechanical strength and bone regeneration during the healing of fractured bones. In this present study, triply periodic minimal surface (TPMS)‐based gyroid and primitive lattice structures were used to design the cellular porous biomimetic scaffolds with different unit cell sizes (4, 5, and 6). The fused filament fabrication‐based 3D printing technology was used for the fabrication of polylactic acid scaffolds. The surface morphology and mechanical compressive strength of differently structured scaffolds were observed using scanning electron microscopy and a universal testing machine. The unit cell size of 4 showed higher compressive strength in both gyroid and primitive structured scaffolds compared to unit cell sizes 5 and 6. Moreover, the gyroid structured scaffolds have higher compressive strengths as compared to primitive structured scaffolds due to the higher bonding surface area at the intercalated layers of the scaffold. Hence, the mechanical strength of scaffolds can be tailored by varying the unit cell size and cellular structures to avoid stress shielding and ensure implant safety. These TPMS‐based scaffolds are promising and can be used as bone substitute materials in tissue engineering and orthopedic applications.

Analysis of gelatin secondary structure in gelatin/keratin-based biomaterials

The possibility of using protein-based materials as cellular scaffold strongly depends on protein conformation, and several attempts have been made by researchers to obtain scaffold with morphology miming the extracellular matrix. It is widely recognized that the secondary structure of proteins affects the mechanical and biological properties of protein-based scaffolds. However, few studies have been published, and an exhaustive explanation is still missing. In this work the study of the gelatin structure in gelatin-based materials and the investigation of the possible correlations between structure, mechanical and biological features is reported.We have examined how the secondary structure of gelatin is affected (i) by the process used to obtain the biomaterials (solvent casting vs. electrospinning), (ii) by the concentration of cross linker (3-(Glycidyloxypropyl)trimethoxysilane) (GPTMS), and (iii) by the raw keratin extract added. Gelatin electrospun materials have shown a content of ordered structure higher than gelatin casted films, likely due to the random coil – α-helix transition occuring during electrospinning. GPTMS gives a decrease of ordered structures in gelatin casted films (random structure increasing from 20% to 60%), while it does not affect the percentage of ordered structure in electrospun samples. In the gelatin/keratin electrospun biomaterials, the presence of keratin produces a decrease of α-helix content from 31% to 2–15% and an increase of β-structures, promoting the conversion from antiparallel to parallel β-sheet. The structure of gelatin affects the mechanical performances of biomaterials. In gelatin/keratin electrospun biomaterials we have found a positive correlation between failure strain and helix conformation and a negative correlation with β-structures. Elastic modulus has opposite correlations. All gelatin-based biomaterials have been tested as scaffold for pre-osteoblastic cells showing good biocompatibility for both casted films and electrospun biomaterials.

New vegetable-waste biomaterials by Lupin albus L. as cellular scaffolds for applications in biomedicine and food

The reprocessing of vegetal-waste represents a new research field in order to design novel biomaterials for potential biomedical applications and in food industry. Here we obtained a biomaterial from Lupinus albus L. hull (LH) that was characterized micro-structurally by scanning electron microscopy and for its antimicrobial and scaffolding properties. A good adhesion and proliferation of human mesenchymal stem cells (hMSCs) seeded on LH scaffold were observed. Thanks to its high content of cellulose and beneficial phytochemical substances, LH and its derivatives can represent an available source for fabrication of biocompatible and bioactive scaffolds. Therefore, a reprocessing protocol of LH was optimized for producing a new LH bioplastic named BPLH. This new biomaterial was characterized by chemico-physical analyses. The water uptake, degradability and antimicrobial properties of BPLH were evaluated, as well as the mechanical properties. A good adhesion and proliferation of both fibroblasts and hMSCs on BPLH were observed over 2 weeks, and immunofluorescence analysis of hMSCs after 3 weeks indicates an initial commitment toward muscle differentiation. Our work represents a new approach toward the recovery and valorization of the vegetal waste showing the remarkable properties of LH and BPLH as cellular waste-based scaffold with potential applications in cell-based food field as well as in medicine for topical patches in wound healing and bedsores treatment.

Fabricating a robust POSS-PCL nanofiber scaffold for nesting of mesenchymal stem cells: potential application in bone tissue regeneration

BackgroundAccording to recent studies, electrospun Poly (Ɛ-caprolactone) (PCL) is an absorbing candidate for the formulation of biocompatible scaffolds used in tissue engineering. Tissue engineering is a set of techniques for producing or reconstructing tissue, whose primary purpose is to restore or improve the function of tissues in the human body. Tissue engineering combines the principles of materials and cell transplantation to develop alternative tissues or promote endogenous regeneration. However, this electrospun scaffold, consisting of PCL, has disadvantages such as low cell adhesion, inactivity of the surface, osteoinduction, and acidic destruction of the scaffold that causes inflammation at the implant site, often making it unsuitable implant. This study aimed to improve PCL base cellular scaffolds with the formulation of polyhedral oligomeric silsesquioxane – Polycaprolactone (POSS-PCL) nanofiber scaffolds. The present research focuses on the synthesis of nanofibers for their cell interaction features, and application in bone tissue engineering and regeneration.ResultsPOSS/ PCL Nanocomposites with 2, 5, and 10 wt.% of POSS were synthesized in the Trichloromethane, then POSS – PCL Nanofibers were prepared by the electrospinning technique. In this study, the structures of nanohybrids and nanofibers have been evaluated by FTIR, HNMR, XRD, SEM, EDX, and DSC. The biocompatibility of formulated POSS-PCL scaffolds was detected using mesenchymal stem cells (MSCs). Then several parameters were examined, involving DCFH ROS detection system, gene expression (cell viability/apoptosis, osteogenesis potentiality, and redox molecular homeostasis.ConclusionsBased on our results, POSS-PCL nano-scaffolds in comparison with PCL have shown a robust potentiality in homing, growth, and differentiation of stem cells.Graphical Synthesis of POSS-PCL Nanofibers and their potential application in Bone Regeneration.

Engineering thixotropic supramolecular gelatin-based hydrogel as an injectable scaffold for cell transplantation

Despite many efforts focusing on regenerative medicine, there are few clinically-available cell-delivery carriers to improve the efficacy of cell transplantation due to the lack of adequate scaffolds. Herein, we report an injectable scaffold composed of functionalized gelatin for application in cell transplantation. Injectable functionalized gelatin-based hydrogels crosslinked with reversible hydrogen bonding based on supramolecular chemistry were designed. The hydrogel exhibited thixotropy, enabling single syringe injection of cell-encapsulating hydrogels. Highly biocompatible and cell-adhesive hydrogels provide cellular scaffolds that promote cellular adhesion, spreading, and migration. The in vivo degradation study revealed that the hydrogel gradually degraded for seven days, which may lead to prolonged retention of transplanted cells and efficient integration into host tissues. In volumetric muscle loss models of mice, cells were transplanted using hydrogels and proliferated in injured muscle tissues. Thixotropic and injectable hydrogels may serve as cell delivery scaffolds to improve graft survival in regenerative medicine.