Nanofibrous Biomaterials Research Articles

Electrical stimulation of Schwann cells on electrospun hyaluronic acid carbon nanotube fibers.

Neurofibromatosis Type 1 (NF1) is a complex genetic disorder characterized by the development of benign neurofibromas, which can cause significant morbidity in affected individuals. While the molecular mechanisms underlying NF1 pathogenesis have been extensively studied, the development of effective therapeutic strategies remains a challenge. This paper presents the development and validation of a novel biomaterial testing model to enhance our understanding of NF1 pathophysiology, disease mechanisms and evaluate potential therapeutic interventions. Our long-term goal is to develop an invitro model of NF1 to evaluate drug targets. We have developed an in vitro system to test the cellular behavior of NF1 patient derived cells on electroconductive aligned nanofibrous biomaterials with electrical stimulatory cues. We hypothesized that cells cultured on electroconductive biomaterial will undergo morphological changes and variations in cell proliferation that could be further enhanced with the combination of exogenous electrical stimulation (ES). In this study, we developed electrospun Hyaluronic Acid-Carbon Nanotube (HA-CNT) nanofiber scaffolds to mimic the axon's topographical and bioelectrical cues that influence neurofibroma growth and development. The cellular behavior was qualitatively and quantitively analyzed through immunofluorescent stains, Alamar blue assays and ELISA assays. Schwann cells from NF1 patients appear to have lost their ability to respond to electrical stimulation in the development and regeneration range, which was seen through changes in morphology, proliferation and NGF release. Without stimulation, the conductive material enhances NF1 SC behavior. Wild-type SC respond to electrical stimulation with increased cell proliferation and NGF release. Using this system, we can better understand the interaction between axons and SC that lead to tumor formation, homeostasis and regeneration.

Electrospun PAN/PEG Nanofibrous Membrane Embedded with a MgO/gC3N4 Nanocomposite for Effective Bone Regeneration.

Developing biomaterial scaffolds using tissue engineering with physical and chemical surface modification processes can improve the bioactivity and biocompatibility of the materials. The appropriate substrate and site for cell attachment are crucial in cell behavior and biological activities. Therefore, the study aims to develop a conventional electrospun nanofibrous biomaterial using reproducible surface topography, which offers beneficial effects on the cell activities of bone cells. The bioactive MgO/gC3N4 was incorporated on PAN/PEG and fabricated into a nanofibrous membrane using electrospinning. The nanocomposite uniformly distributed on the PAN/PEG nanofiber helps to increase the number of induced pores and reduce the hydrophobicity of PAN. The physiochemical characterization of prepared nanoparticles and nanofibers was carried out using FTIR, X-ray diffraction (XRD), thermogravimetry analysis (TGA), X-ray photoelectron spectroscopy (XPS), and water contact angle measurements. SEM and TEM analyses examined the nanofibrous morphology and the structure of MgO/gC3N4. In vitro studies such as on ALP activity demonstrated the membrane's ability to regenerate new bone and healing capacity. Furthermore, alizarin red staining showed the increasing ability of the cell-cell interaction and calcium content for tissue regeneration. The cytotoxicity of the prepared membrane was about 97.09% of live THP-1 cells on the surface of the MgO/gC3N4@PAN/PEG membrane evaluated using MTT dye staining. The soil burial degradation analysis exhibited that the maximum degradation occurs on the 45th day because of microbial activity. In vitro PBS degradation was observed on the 15th day after the bulk hydrolysis mechanism. Hence, on the basis of the study outcomes, we affirm that the MgO/gC3N4@PAN/PEG nanofibrous membrane can act as a potential bone regenerative substrate.

Edible electrospun zein nanofibrous scaffolds close the gaps in biofilm formation ability between microorganisms

Biofilm is an important survival mode of microorganisms in nature. Biofilm culture is supposed to be a way of learning from nature to endow microorganisms with a strong tolerance. However, microorganisms possess different biofilm formation abilities, and universal scaffolds, especially edible scaffolds, suitable for fast biofilm formation are not found yet. Zein is a hydrophobic and biocompatible prolamine-rich protein from corn and is one of the most used biomacromolecules now. In this work, natural zein was utilized to produce electrospun zein nanofibrous biomaterial. The results demonstrate that edible electrospun zein nanofibrous scaffolds significantly enhance biofilm formation, where bacterial probiotics and yeasts are 0.9–1.4 Log cfu/cm2 (8–25 × ) and 1.7–3.3 Log cfu/cm2 (50–2000 × ) higher than the values on polystyrene plates and zein films, respectively. Gaps in biofilm formation abilities between bacteria and yeasts are narrowed from 1.7–1.8 Log cfu/cm2 (50–63 × ) to 0.5–0.6 Log cfu/cm2 (3–4 × ), respectively. Biofilms quickly formed on electrospun zein nanofibrous scaffolds before the occurrence of serious swelling deformation of the scaffolds. This is the first attempt to use edible electrospun fibrous scaffolds based on natural biomacromolecules for enhancing biofilm formation, crucially important for the application of probiotics and yeast in food and medical industries. Electrospun zein nanofibrous scaffolds can serve as powerful tools to enhance the biofilm formation of valuable food microorganisms and close the huge gaps in biofilm formation abilities between microorganisms, providing a convenient and universal strategy to produce biofilm-phenotyped probiotics and yeasts.

Biomimetic Electrospun PLLA/PPSB Nanofibrous Scaffold Combined with Human Neural Stem Cells for Spinal Cord Injury Repair

Spinal cord injury (SCI) treatment remains a worldwide challenge considering its limited self-repair capacity. The transplantation of neural stem cells (NSCs) has been proposed as a potential approach to restoring neurological function by promoting axonal regeneration. While nanofibrous biomaterials provide the biomimetic microenvironment for the immobilization and growth of transplanted NSCs. In this study, a biomimetic poly(polyol sebacate)-based elastomeric nanofibrous scaffold developed with poly(l-lactic acid) (PLLA) and poly(polycaprolactone triol-co-sebacic acid-co-BES sodium salt) (PPSB) was fabricated by electrospinning and combined with human NSCs (hNSCs) for SCI treatment. The electrospun PLLA/PPSB nanofibrous scaffold containing 40 wt % PPSB demonstrated a highly porous microstructure, sulfonate group modification, strong hydrophilicity, suitable degradation performance, and good mechanical properties. The scaffold promoted the proliferation and further differentiation of hNSCs into neuronal cells. Moreover, the transplantation of hNSCs-loaded PLLA/PPSB nanofibrous scaffold attenuated the inflammatory response, enhanced the regeneration of neurons, and inhibited the growth of astrocytes in the lesion areas, thereby promoting the functional restoration of the spinal cord in rats with completely transected SCI. Thus, we conclude that the hNSCs-loaded PLLA/PPSB composites could promote the repair of spine cord injury. The findings could provide insight into the combined treatment strategies for SCI based on NSCs and bioactive biomaterials.

Alternating field electrospinning of blended fish gelatin/poly(ε-caprolactone) nanofibers

Blended nanofibrous biomaterials from natural and synthetic sources show promise for better biointegration. This study explores high-yield alternating field electrospinning (AFES) of blended cold-water fish skin gelatin (FGEL) and polycaprolactone (PCL) nanofibrous meshes with up to 30 wt% PCL at 7.8–14.4 g/h fiber productivity, depending on the composition. FGEL/PCL nanofibers reveal smooth surface morphology and 237–313 nm average diameters after thermal crosslinking. FTIR analysis indicated little FGEL/PCL interaction and notable changes in PCL crystallinity in the crosslinked nanofibers. A 14-days in-vitro analysis shows good cellular viability and nanofibrous FGEL/PCL mesh stability. Results demonstrate that AFES provides efficient, scalable production of blended FGEL/PCL nanofibrous biomaterials with suitable characteristics.

A systematic study of nano-based fibrous systems: Diagnostic and therapeutic approaches for dementia control.

Nano-based systems provide many advantages, including eluding gastrointestinal and first-pass metabolism of the drug and improving the potential advantage of reduced doses of drugs for an equal or better therapeutic effect compared to other parts of oral administration. Over the last few years, protein-based nanofibrous biomaterials have been used for better controlling dementia. PubMed, Scopus, and ISI Web of Science were consulted for available articles on nano-based fibrous systems for the treatment and diagnosis of dementia (up to October 2022). Of 725 articles that were identified and evaluated, only 19 were included. Eleven studies evaluated nanofibrous electrospun biomaterials for better dementia control. Among these, four investigated marker/biomarker detection for the early diagnosis of dementia. Two from four studies conducted hydrogel-based nanofibrous for Alzheimer's disease (AD) treatment. Additionally, four studies inspected stem cell (SC) transplantation on nano-based fibrous scaffolds for better treatment of dementia. Finally, two from the final four studies considered nano-based fibrous systems for the enhanced treatment of dementia. Our study concluded that nano-based fibrous platforms, exclusively peptide/protein-based nanofibrous scaffolds made from biomaterials, can be applied for dementia management by either diagnostic or therapeutic approaches specific in purpose-designed electrospun nanofibrous scaffolds.

Massive production of fibroin nano-fibrous biomaterial by turbulent co-flow

Among the different polymers (proteins, polysaccharides, etc.) that make up natural fibers, fibroin is a protein produced by silk spinning animals, which have developed an optimized system for the conversion of a highly concentrated solution of this protein into high-performance solid fibers. This protein undergoes a self-assembly process in the silk glands that result from chemical gradients and by the application of mechanical stresses during the last step of the process. In the quest for a process that could mimic natural spinning at massive scales, we have discovered that turbulence offers a novel and promising solution: a turbulent liquid jet can be formed by a chemically green and simple coagulating liquid (a diluted solution of acetic acid in etanol) co-flowing with a concentrated solution of fibroin in water by the use of a Flow Blurring nebulizer. In this system, (a) the co-flowing coagulant liquid extracts water from the original protein solution and, simultaneously, (b) the self-assembled proteins are subjected to mechanical actions, including splitting and stretching. Given the non-negligible produced content with the size and appearance of natural silk, the stochastic distribution of those effects in our process should contain the range of natural ones found in animals. The resulting easily functionalizable and tunable one-step material is 100% biocompatible, and our method a perfect candidate to large-scale, low-cost, green and sustainable processing of fibroin for fibres and textiles.

RGO/Silk Fibroin-Modified Nanofibrous Patches Prevent Ventricular Remodeling via Yap/Taz-TGFβ1/Smads Signaling After Myocardial Infarction in Rats.

Objective: After acute myocardial infarction (AMI), the loss of cardiomyocytes and dysregulation of extracellular matrix homeostasis results in impaired cardiac function and eventually heart failure. Cardiac patches have emerged as a potential therapeutic strategy for AMI. In this study, we fabricated and produced reduced graphene oxide (rGO)/silk fibroin-modified nanofibrous biomaterials as a cardiac patch to repair rat heart tissue after AMI and investigated the potential role of rGO/silk patch on reducing myocardial fibrosis and improving cardiac function in the infarcted rats.Method: rGO/silk nanofibrous biomaterial was prepared by electrospinning and vacuum filtration. A rat model of AMI was used to investigate the ability of patches with rGO/silk to repair the injured heart in vivo. Echocardiography and stress–strain analysis of the left ventricular papillary muscles was used to assess the cardiac function and mechanical property of injured hearts treated with this cardiac patch. Masson's trichrome staining and immunohistochemical staining for Col1A1 was used to observe the degree of myocardial fibrosis at 28 days after patch implantation. The potential direct mechanism of the new patch to reduce myocardial fibrosis was explored in vitro and in vivo.Results: Both echocardiography and histopathological staining demonstrated improved cardiac systolic function and ventricular remodeling after implantation of the rGO/silk patch. Additionally, cardiac fibrosis and myocardial stiffness of the infarcted area were improved with rGO/silk. On RNA-sequencing, the gene expression of matrix-regulated genes was altered in cardiofibroblasts treated with rGO. Western blot analysis revealed decreased expression of the Yap/Taz-TGFβ1/Smads signaling pathway in heart tissue of the rGO/silk patch group as compared with controls. Furthermore, the rGO directly effect on Col I and Col III expression and Yap/Taz-TGFβ1/Smads signaling was confirmed in isolated cardiofibroblasts in vitro.Conclusion: This study suggested that rGO/silk improved cardiac function and reduced cardiac fibrosis in heart tissue after AMI. The mechanism of the anti-fibrosis effect may involve a direct regulation of rGO on Yap/Taz-TGFβ1/Smads signaling in cardiofibroblasts.

Recent advances in surface modification of biopolymeric nanofibrous scaffolds

Nanofibrous biomaterials, because of their structural similarity to the extracellular matrix, can be employed as a scaffold in tissue engineering. The use of biopolymers to nanofibers fabrication attracts a great deal of attention. However, sometimes these nanofibers do not support specific cell behaviors. To address this drawback, surface modification of these structures has been actively investigated. Just a while ago, nanofibrous scaffolds have been modified employing various techniques to provide an appropriate microenvironment for protecting cell functions. Modification of bulk or surfaces of the nanofibrous scaffolds via different methods can promote cell adhesion, growth, proliferation, migration, and differentiation. In this paper, we are going to discuss the different and new approaches to surface modification of polymeric nanofibers that can influence scaffolds characteristics.

Simple conversion of 3D electrospun nanofibrous cellulose acetate into a mechanically robust nanocomposite cellulose/calcium scaffold

Cellulose and its derivatives are widely used as nanofibrous biomaterials, but obtaining 3D cellulose nanofibers is difficult and relevant research is scarce. In the present study, we propose a simple method for converting electrospun 3D cellulose acetate/lactic acid nanofibers via calcium hydroxide treatment into a 3D cellulose/calcium lactate nanocomposite matrix. The conversion resulted in producing a stronger nanofibrous matrix (1.382 MPa vs. 0.112 MPa) that is more hydrophilic and cell-friendly compared to the untreated cellulose acetate/lactic acid group. The successful conversion was verified via FTIR, XPS, TGA, DTG, and XRD. The ability of the scaffolds to provide a suitable environment for cell growth and infiltration was verified by CCK assay and confocal microscopy. The porous nature, mechanical strength, and presence of calcium make the 3D cellulose/calcium lactate matrix a promising material for bone tissue engineering.

Functional Nanofibrous Biomaterials of Tailored Structures for Drug Delivery-A Critical Review.

Nanofibrous biomaterials have huge potential for drug delivery, due to their structural features and functions that are similar to the native extracellular matrix (ECM). A wide range of natural and polymeric materials can be employed to produce nanofibrous biomaterials. This review introduces the major natural and synthetic biomaterials for production of nanofibers that are biocompatible and biodegradable. Different technologies and their corresponding advantages and disadvantages for manufacturing nanofibrous biomaterials for drug delivery were also reported. The morphologies and structures of nanofibers can be tailor-designed and processed by carefully selecting suitable biomaterials and fabrication methods, while the functionality of nanofibrous biomaterials can be improved by modifying the surface. The loading and releasing of drug molecules, which play a significant role in the effectiveness of drug delivery, are also surveyed. This review provides insight into the fabrication of functional polymeric nanofibers for drug delivery.

ECM-mimicking nanofibrous matrix coaxes macrophages toward an anti-inflammatory phenotype: Cellular behaviors and transcriptome analysis

An in-depth understanding of biomaterial cues to selectively polarize macrophages is beneficial in the design of “immuno-informed” biomaterials that positively interact with the immune system to dictate a favorable macrophage response following implantation. Given the promising future of ECM-mimicking nanofibrous biomaterials in biomedical application, it is essential to elucidate how their intrinsic cues, especially the nanofibrous architecture, affect macrophages. In the present study, we evaluated how the nanofibrous architecture of a gelatin matrix modulated macrophage responses from the perspectives of cellular behaviors and a transcriptome analysis. In our results, the nanofibrous surface attenuated M1 polarization and down-regulated the inflammatory responses of macrophages compared with a smooth surface. Besides, the cell-material interaction was up-regulated and the adhered macrophages tended to maintain an original, non-polarized state on the nanofibrous matrix. Accordingly, whole transcriptome analysis revealed that nanofibrous architecture up-regulated the pathways related to ECM-receptor interaction and down-regulated pathways related to pro-inflammation. This study provides a panoramic view of the interaction between macrophages and nanofibers, and offers valuable information for the design of immunomodulatory ECM-mimicking biomaterials for tissue regeneration.

Multiscale constitutive model with progressive recruitment for nanofibrous scaffolds

Biomedical applications need tailor-made scaffolds that exhibit biomimetic mechanical properties. In this context, electrospinning has emerged as a technique with promising features for their production. However, the electrospun scaffolds mechanical behavior as a function of the microstructure and nanofiber properties is still poorly understood. Besides, multiscale constitutive modeling appears as a powerful design tool, not only able to characterize electrospun structures, but also to determine the fiber properties and scaffold microstructure that would achieve the objective response. With focus in this last aspect, we developed a multiscale constitutive model for nanofibrous structures that takes into account the material constitutive properties, scaffold microstructure, and nanofiber progressive recruitment. A statistical approach of the nanofibers tortuosity with a modified Gaussian distribution was adopted, which allowed for reproducing the scaffolds macroscopic nonlinear mechanical behavior. It was observed that such behavior arises even if the nanofibers response is considered as mechanically linear. Experimental data from pressure vs. diameter inflation tests of electrospun tubular scaffolds was used to validate the model. In addition, the influence of the microstructural parameters upon the macroscopic constitutive behavior was studied. Finally, the model parameters were adjusted to obtain a vascular graft able to reproduce the mechanical response of a target natural tissue. The current study presents a step towards understanding, characterizing, and optimizing the mechanical properties of nanofibrous biomaterials.

Application of polycaprolactone, chitosan, and collagen composite as a nanofibrous mat loaded with silver sulfadiazine and growth factors for wound dressing.

Fabrication of nanofibrous biomaterials composed of natural and synthetic materials that incorporated with antibiotic and growth factors with controlled release manner is an attractive topic in wound healing. The purpose of this study was to prepare optimal composite of materials as biomimetic nanofibrous mats for application in wound healing. The mat was prepared of polycaprolactone (PCL) in the bottom, chitosan/poly ethylene oxide (Cs/PEO) in the middle, and PCL/collagen (PCL/Coll) in the top layer. A panel of standard characterization tests of nanofibrous mat was performed and its compatibilities in strength and integration were confirmed. Middle layer was loaded with epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF), and silver sulfadiazine (SSD) was incorporated in the bottom layer as an anti-infection factor. Then, on the dorsum of rats, a 400-mm2 wound was created and surrounded by a silicone ring to control the usual tissue contractions. Nanofibrous mats with or without growth factors were applied as wound dressings and at day 14, the healing process was evaluated. At day 14, the treated group by designed mat showed faster epithelialization and angiogenesis. Silicone ring in the test group was desirable in wound closure compared to the control group. Reformation of skin tissue was manifested in a shorter time. This composite nanofibrous mat could be introduced as a dynamic and effective candidate for wound dressing.

A new glioblastoma cell trap for implantation after surgical resection

Glioblastoma (GB) is a highly infiltrative tumor, recurring, in 90% of cases, within a few centimeters of the surgical resection cavity, even with adjuvant chemo/radiotherapy. Residual GB cells left in the margins or infiltrating the brain parenchyma shelter behind the extremely fragile and sensitive brain tissue and may favor recurrence. Tools for eliminating these cells without damaging the brain microenvironment are urgently required. We propose a strategy involving the implantation, into the tumor bed after resection, of a scaffold to concentrate and trap these cells, to facilitate their destruction by targeted therapies, such as stereotactic radiosurgery. We used bacterial cellulose (BC), an easily synthesized and modifiable random nanofibrous biomaterial, to make the trap. We showed that the structure of BC membranes was ideal for trapping tumor cells and that BC implants were biocompatible with brain parenchyma. We also demonstrated the visibility of BC on magnetic resonance imaging, making it possible to follow its fate in clinical situations and to define the target volume for stereotactic radiosurgery more precisely. Furthermore, BC membranes can be loaded with chemoattractants, which were released and attracted tumor cells in vitro. This is of particular interest for trapping GB cells infiltrating tissues within a few centimeters of the resection cavity. Our data suggest that BC membranes could be a scaffold of choice for implantation after surgical resection to trap residual GB cells. Statement of SignificanceGlioblastoma is a highly infiltrative tumor, recurring, in 90% of cases, within a few centimeters of the surgical resection cavity, even with adjuvant chemo/radiotherapy. Residual tumor cells left in the margins or infiltrating the brain parenchyma shelter behind the extremely fragile and sensitive brain tissue and contribute to the risk of recurrence. Finding tools to eliminate these cells without damaging the brain microenvironment is a real challenge. We propose a strategy involving the implantation, into the walls of the surgical resection cavity, of a scaffold to concentrate and trap the residual tumor cells, to facilitate their destruction by targeted therapies, such as stereotactic radiosurgery.

Reduced graphene oxide functionalized nanofibrous silk fibroin matrices for engineering excitable tissues

Tissue engineering has provided an alternative strategy for the regeneration of functional tissues for drug screening and disease intervention. The central challenge in the development of mature and functional excitable tissues is to design and construct advanced conductive biomaterials that can guide cells to form electrically interconnected networks. The objective of this study was to develop reduced graphene oxide modified silk nanofibrous biomaterials with controllable surface deposition on the nanoscale. A vacuum filtration system was applied to attain reduced graphene oxide nanolayer deposition. The results demonstrate that with this method, a uniform and compact reduced graphene oxide nanolayer was formed, and the conductivity and nanofibrous morphology of the materials was well controlled. The composite nanofibrous scaffolds were applied for the engineering of cardiac tissues and demonstrated a great ability to promote tissue formation and functions, including the expression of cardiac-specific proteins, the formation of sarcomeric structures and gap junctions, and tissue contraction. External electrical stimulation further enhanced the maturation level of cardiac tissues cultured on these conductive scaffolds. All these results demonstrated the great potential of reduced graphene oxide functionalized silk biomaterials fabricated using our method for recapitulating electrical microenvironments for the regeneration of functional excitable tissues.

Nanofibers Regulate Single Bone Marrow Stem Cell Osteogenesis via FAK/RhoA/YAP1 Pathway.

Understanding cell-material interactions is a prerequisite for the development of bio-inspired materials for tissue regeneration. While nanofibrous biomaterials have been widely used in tissue regeneration, the effects of nanofibrous architecture on stem cell behaviors are largely ambiguous because the previous biomaterial systems used for nanofiber-cell interactions could not exclude the interference of cell-cell interactions. In this study, we developed a unique micropatterning technology to confine one single stem cell in a microisland of the nanofibrous micropatterned matrix; therefore, eliminating any potential intercellular communications. The nanofibrous micropatterned matrix, which mimicked both the physical architecture and chemical composition of natural extracellular matrix, was fabricated by a combination of electrospinning, chemical crosslinking, and UV-initiated photolithography. Compared to the non-nanofibrous architecture, a bone marrow mesenchymal stem cell (BMSC) cultured on the nanofibrous microisland exhibited a more in vivo-like morphology, a smaller spreading area, less focal adhesion, and fewer stress fibers. The BMSC cultured on the nanofibrous microisland also had higher alkaline phosphatase activity, indicating nanofibrous architecture promoted BMSC differentiation. A mechanistic study reveals that nanofibers regulate single BMSC osteogenesis via the FAK/RhoA/YAP1 pathway. The nanofibrous micropatterned matrix developed in this study is an excellent platform to promote the fundamental understanding of cell-matrix interactions, ultimately provide valuable insights for the development of novel bio-inspired scaffolds for tissue regeneration.

Incorporation and selective removal of space-forming nanofibers to enhance the permeability of cytocompatible nanofiber membranes for better cell growth

Abstract Nanofibrous biomaterials fabricated by electrospinning attract increasing attention. However, electrospun nanofibers are stacked tightly, thus restricting cell infiltration and nutrient supply. To overcome this drawback, we developed three types of cytocompatible nanofiber membranes, namely (1) electrospun chitosan/gelatin/PEO (CGP) composite membrane, (2) co-electrospun CGP/E membrane containing CGP and Eudragit (E) nanofibers, (3) CGP (E removed) membrane which was obtained by selective removal of E nanofibers from CGP/E membrane. The permeability of albumin through CGP, CGP/E, and CGP (E removed) nanofiber membranes increased from 1.50 × 10−11 to 6.19 × 10−11 and further to 15.3 × 10−11 m2/s, respectively. Hence, incorporating large-diameter (space-forming) E nanofibers with CGP nanofibers enhanced the permeability of CGP/E membrane. Moreover, selectively removing E nanofibers from CGP/E membrane further enlarged pore size and created more permeable CGP (E removed) membrane. Membrane strength and stability were reinforced by crosslinking with glutaraldehyde for 2.5 h. To verify our approach, stem cells (KP-hMSCs) were covered by CGP (E removed) or CGP membrane and cultured for 7 days. The cell density underneath CGP (E removed) membrane was about 1.7 times of that underneath CGP membrane, indicating that improved cell growth (proliferation) occurred under CGP (E removed) membrane. Therefore, our approach to create more permeable nanofiber membranes for better cell growth is successful and can be utilized for fabricating various nanofibrous biomaterials.

Fabrication and In Vitro Characterization of Bioactive Glass/Nano Hydroxyapatite Reinforced Electrospun Poly(ε-Caprolactone) Composite Membranes for Guided Tissue Regeneration.

Background: Current resorbable and non-resorbable membranes act as a physical barrier to avoid connective and epithelial tissue downgrowth into the defect, favoring the regeneration of periodontal tissues. These conventional membranes possess many structural and bio-functional limitations. We hypothesized that the next-generation of guided tissue regeneration (GTR) membranes for periodontal tissue engineering will be a biologically active, spatially designed nanofibrous biomaterial that closely mimics the native extra-cellular matrix (ECM). Methods: GTR membranes made of poly(ε-Caprolactone) with a molecular weight of 80,000 reinforced with different weight concentrations of nano-Hydroxyapatite/Bioactive glass (2%, 5%, 10%, 15%) is fabricated by the method of electrospinning. After fabrication, in vitro properties are evaluated. Results: The electrospun nanofibrous membranes possessed excellent mechanical properties initially and after one month of degradation in phosphate buffer solution (PBS). Moreover, none of the fabricated membranes were found to be cytotoxic at lower concentrations and higher concentrations. Comparing the overall properties, PCL (poly(e-caprolactone)) + BG (Bioactive glass) 2% exhibited superior cell attachment and percentage of viable cells, increased fiber and pore diameter which satisfies the ideal properties needed for GTR membranes. Conclusion: Composite nanofibrous membranes prepared by electrospinning are suitable for use as a GTR membrane and are a useful prototype for further development of a final membrane for clinical use.

In vitro and in vivo studies of a novel bacterial cellulose-based acellular bilayer nanocomposite scaffold for the repair of osteochondral defects.

Bacterial cellulose (BC) is a naturally occurring nanofibrous biomaterial which exhibits unique physical properties and is amenable to chemical modifications. To explore whether this versatile material can be used in the treatment of osteochondral defects (OCD), we developed and characterized novel BC-based nanocomposite scaffolds, for example, BC-hydroxyapatite (BC-HA) and BC-glycosaminoglycans (BC-GAG) that mimic bone and cartilage, respectively. In vitro biocompatibility of BC-HA and BC-GAG scaffolds was established using osteosarcoma cells, human articular chondrocytes, and human adipose-derived mesenchymal stem cells. On subcutaneous implantation, the scaffolds allowed tissue ingrowth and induced no adverse immunological reactions suggesting excellent in vivo biocompatibility. Implantation of acellular bilayered scaffolds in OCD created in rat knees induced progressive regeneration of cartilage tissue, deposition of extracellular matrix, and regeneration of subchondral bone by the host cells. The results of micro-CT revealed that bone mineral density and ratio of bone volume to tissue volume were significantly higher in animals receiving bilayered scaffold as compared to the control animals. To the best of our knowledge, this study proves for the first time, the functional performance of acellular BC-based bilayered scaffolds. Thus, this strategy has great potential for clinical translation and can be used in repair of OCD.