The role of inflammatory mediators and matrix metalloproteinases (MMPs) in the progression of osteoarthritis.

Osteoarthritis (OA) is a chronic musculoskeletal disorder characterized by an imbalance between (synthesis) and catabolism (degradation) in altered homeostasis of articular cartilage mediated primarily by the innate immune system. OA degenerates the joints resulting in synovial hyperplasia, degradation of articular cartilage with damage of the structural and functional integrity of the cartilage extracellular matrix, subchondral sclerosis, osteophyte formation, and is characterized by chronic pain, stiffness, and loss of function. Inflammation triggered by factors like biomechanical stress is involved in the development of osteoarthritis. In OA apart from catabolic effects, anti-inflammatory anabolic processes also occur continually. There is also an underlying chronic inflammation present, not only in cartilage tissue but also within the synovium, which perpetuates tissue destruction of the OA joint. The consideration of inflammation in OA considers synovitis and/or other cellular and molecular events in the synovium during the progression of OA. In this review, we have presented the progression of joint degradation that results in OA. The critical role of inflammation in the pathogenesis of OA is discussed in detail along with the dysregulation within the cytokine networks composed of inflammatory and anti-inflammatory cytokines that drive catabolic pathways, inhibit matrix synthesis, and promote cellular apoptosis. OA pathogenesis, fluctuation of synovitis, and its clinical impact on disease progression are presented here along with the role of synovial macrophages in promoting inflammatory and destructive responses in OA. The role of interplay between different cytokines, structure, and function of their receptors in the inter-cellular signaling pathway is further explored. The effect of cytokines in the increased synthesis and release of matrix-decomposing proteolytic enzymes, such as matrix metalloproteinase (MMPs) and a disintegrin-like and metalloproteinase with thrombospondin motif (ADAMTS), is elaborated emphasizing the potential impact of MMPs on the chondrocytes, synovial cells, articular and periarticular tissues, and other immune system cells migrating to the site of inflammation. We also shed light on the pathogenesis of OA via oxidative damage particularly due to nitric oxide (NO) via its angiogenic response to inflammation. We concluded by presenting the current knowledge about the tissue inhibitors of metalloproteinases (TIMPs). Synthetic MMP inhibitors include zinc binding group (ZBG), non-ZBG, and mechanism-based inhibitors, all of which have the potential to be therapeutically beneficial in the treatment of osteoarthritis. Improving our understanding of the signaling pathways and molecular mechanisms that regulate the MMP gene expression, may open up new avenues for the creation of therapies that can stop the joint damage associated with OA.

Iodine functionalized 2,5-dimethoxy-2,5-dihydrofuran (DHFI) crosslinked whey protein-derived carbon nanodots (WCND) for antibacterial application.

Whey protein-derived carbon nanodots (WCND) were synthesized using the microwave irradiation method, and its amine-rich surface functionality was crosslinked with covalently bound Iodine functionalized 2,5-dimethoxy-2,5-dihydrofuran (DHFI) to produce WCND-DHFI. The physicochemical characterization of both WCND and WCND-DHFI was performed and compared to comprehend the consequence of iodination on the characteristics of WCND. The suitability of CND in biological environments was evaluated through in vitro cytocompatibility and Chorioallantoic Membrane (CAM) assay, as well as a hemocompatibility study. WCND-DHFI has shown enhanced cell viability against WCND. Further, the antibacterial properties of both CNDs were studied against both gram-positive and gram-negative bacterial strains, representing an enhancement in antibacterial activity after DHFI crosslinking. WCND-DHFI has depicted a stable and prominent bacteriostatic activity for up to 6 h for both strains of bacteria. WCND-DHFI has denoted a 99.996% and 99.999% loss of bacterial viability for gram-positive and negative strains, respectively. Novel surface functionalization portrays an improvement in antibacterial activity. Transmission and scanning electron microscopy represent the cell wall rupturing by the WCND-DHFI, resulting in bacterial death. The ROS-mediated bacteriostatic mechanism of WCND-DHFI has been explored through assessing lipid peroxidation and protein oxidation assay. Moreover, the oxidative damage of DNA also has been explored. WCND-DHFI is performing as a promising cytocompatible and hemocompatible material for antibacterial applications.

Apoptosis-targeted gene therapy for non-small cell lung cancer using chitosan-poly-lactic-co-glycolic acid -based nano-delivery system and CASP8 and miRs 29A-B1 and 34A.

Non-small cell lung cancer (NSCLC) is a leading cause of cancer-related deaths worldwide, with resistance to apoptosis being a major driver of therapeutic resistance and aggressive phenotype. This study aimed to develop a novel gene therapy approach for NSCLC by targeting resistance to apoptosis. Loss of function mutations of caspase 8 (CASP8) and downregulation of microRNAs (miRs) 29A-B1 and 34A were identified as key contributors to resistance to apoptosis in NSCLC. A biodegradable polymeric nano-gene delivery system composed of chitosan-poly-lactic-co-glycolic acid was formulated to deliver initiator CASP8 and miRs 29A-B1 and 34A. The nano-formulation efficiently encapsulated the therapeutic genes effectively internalized into NSCLC cells and induced significant apoptosis. Evaluation of the nano-formulation in A549 tumor spheroids showed a significant increase in apoptosis within the core of the spheroids, suggesting effective penetration into the spheroid structures. We provide a novel nano-formulation that demonstrate therapeutic potential for suicidal gene therapy in NSCLC.

Irreversible Electroporation as an Alternative to Wound Debridement Surgery.

Debridement is a standard part of wound care that is used on both acute and chronic wounds. Current methods of wound debridement include: autolytic based on the natural immune response, surgical, enzymatic based on application of exogenous proteases, mechanical using water jets and ultrasound, and biological using live organisms such as maggots. The choice of individual methods involves a trade-off between speed of treatment, selectivity, and pain. Irreversible electroporation via the application of pulsed electric fields has been used as a novel approach for deep tissue ablation, sometimes in conjunction with chemotherapy, as in the case of tumors, and also in cases where high precision is needed in otherwise very fragile tissues, such as for treating diabetic neuropathy and in epicardial atrial ablation. This method could be readily extended to wound care as it is both rapid and relatively painless, and it is also effective at decreasing bacterial load and clearing biofilms. Furthermore, the process primarily targets cells leaving the extracellular matrix relatively intact, thus providing a suitable natural scaffold for host cellular invasion and regrowth. A unique aspect of the use of pulsed electric fields is that around the region where ablation is perfomed, electric fields of lower energy are dissipated into the healthy tissue. There is a range of electric fields that are known to stimulate cellular functions, in particular migration and proliferation, and that may contribute to the healing process after electroporation. While irreversible electroporation is a potentially useful alternative to other debridement methods, future clinical application awaits technological advances in electrode design that will enable precise delivery of the therapy in wounds of various sizes and depths.

Direct 3D Printing of Seashell Precursor toward Engineering a Multiphasic Calcium Phosphate Bone Graft.

Multiphasic calcium phosphate (Ca-P) has widely been explored for bone graft replacement. This study represents a simple method of developing osteoinductive scaffolds by direct printing of seashell resources. The process demonstrates a coagulation-assisted extrusion-based three-dimensional (3D) printing process for rapid fabrication of multiphasic calcium phosphate-incorporated 3D scaffolds. These scaffolds demonstrated an interconnected open porous architecture with improved compressive strength and higher surface area. Multiphasic calcium phosphate (Ca-P) and hydroxyapatite present in the multi-scalar naturally resourced scaffold displayed differential protein adsorption, thus facilitating cell adhesion, migration, and differentiation, resulting in enhanced deposition of the extracellular matrix. The microstructural and physicochemical attributes of the scaffolds also lead to enhanced stem cell differentiation as witnessed from gene and protein expression analysis. Furthermore, the histological study of subcutaneous implantation evidently portrays promising biocompatibility without foreign body reaction. Neo-tissue in-growth was manifested with abundant blood vessels, thus indicative of excellent vascularization. Notably, cartilaginous and proteoglycan-rich tissue deposition indicated ectopic bone formation via an endochondral ossification pathway. The hierarchical interconnected porous architectural tribology accompanied with multiphasic calcium phosphate composition manifests its successful implication in enhancing stem cell differentiation and promoting excellent tissue in-growth, thus making it a plausible alternative in bone tissue engineering applications.

Carbon nano dot decorated copper nanowires for SERS-Fluorescence dual-mode imaging/anti-microbial activity and enhanced angiogenic activity.

Copper nanoparticles are explored significantly for their antimicrobial activity, especially for antibiotic-resistant strain infections. However, copper has severe toxic responses and mostly it is due to its generation capability of reactive oxygen species (ROS) molecules while interacting with in vitro or in vivo systems. In the current study, wire shaped copper nanostructures were synthesized via microwave irradiation with single step doping of carbon nanodots (CDs). The synthesized material (CuCs) was characterized by UV-Vis spectroscopy, fluorescence spectroscopy, FTIR, TEM, FESEM, XRD, DLS, and XPS. The fluorescence spectroscopy, microscopy and Raman spectroscopy results suggested CuCs to work well as a bi-modal imaging nanoprobe (fluorescence/SERS). The cell culture studies prove significant cytocompatibility and ROS scavenging property of the samples with respect to control. Further, CuCs-gelatin nanocomposite thin films were prepared and implanted into rodent deep wound model. The histological study has showed enhanced angiogenesis in the subcutaneous region. The results were validated by immuno-histochemistry. The ROS scavenging and enhanced angiogenesis were validated via gene expression studies and a HIF-α induced enhanced angiogenesis mechanism was also proposed for better wound healing.

Differential Cell Death and Regrowth of Dermal Fibroblasts and Keratinocytes After Application of Pulsed Electric Fields.

Background: High-powered pulsed electric fields (PEF) may be used for tissue debridement and disinfection, while lower PEF intensities may stimulate beneficial cellular responses for wound healing. We investigated the dual effects of nonuniform PEF on cellular death and stimulation. Methods: Dermal fibroblast or keratinocyte monolayers were exposed to PEF induced by two needle electrodes (2 mm apart). Voltages (100-600 V; 1 Hz; 70 micros pulse width; 90 pulses/cycle) were applied between the two electrodes. Controls consisted of similar monolayers subjected to a scratch mechanical injury. Results: Cell growth and closure of the cell-free gap was faster in PEF-treated cell monolayers versus scratched ones. Media conditioned from cells pre-exposed to PEF, when applied to responder cells, stimulated greater proliferation than media from scratched monolayers. Conclusions: PEF treatment causes the release of soluble factors that promote cell growth, and thus may play a role in the accelerated healing of wounds post PEF.

Manganese oxide-carbon quantum dots nano-composites for fluorescence/magnetic resonance (T1) dual mode bioimaging, long term cell tracking, and ROS scavenging.

Multimodal long-term imaging probes with capability of extracting complementary information are highly important in biomedical engineering for disease diagnosis and monitoring of therapeutics distribution. However, most of the theranostics probes used are transient and have inherent problem of toxicity mostly related to generation of free radicals. In current study, a simple microwave assisted synthesis of multimodal imaging nanoprobe (T1 contrast in MR/fluorescence) is reported via doping carbon quantum dots into manganese oxide nanoparticles. The nanostructures were characterized by US-Vis spectroscopy, fluorescence spectroscopy, FTIR, Raman spectroscopy, TEM, XRD, AFM and XPS. The average particle size was observed to be around 20-40 nm with a height of 7-9 nm and approximate quantum yield of 0.23. The nanostructures were useful for bio imaging and cell tracking via fluorescence microscopy up to 12 generations with nominal cytotoxicity. The material was capable of scavenging free radicals from cellular microenvironment and downregulate gene expression of free radical scavenging enzymes. The material has significant relaxivity (r1) value of 3.98 mM-1.sec-1 at 1.5 T. It was also observed to create significant contrast with high circulation time (30 min) and renal clearance property. The histological analysis of kidney and liver sections were observed to have no significant toxicity from the nanostructure.

Doping of carbon nanodots for saving cells from silver nanotoxicity: A study on recovering osteogenic differentiation potential.

Silver nanoparticles are explored for many advanced biological applications including the development of antimicrobial surfaces on implants, SERS imaging, nanotherapeutics, biosensing and much more. However, recent research findings suggest silver nanoparticles provide blockade of differentiation of mesenchymal stem cells (MSCs), especially into osteogenic developmental pathway via generation of reactive oxygen species. These studies suggest that the application of silver nanoparticles in medical implants should be prohibited. In the current study, carbon nanodots (CND) supported silver clusters (AgC) is explored as a remedy to this problem. The nanostructure was synthesized in microwave irradiation induced rapid method and characterization was conducted via UV-Vis spectroscopy, fluorescence spectroscopy, HRTEM, XRD, FTIR, Raman spectroscopy, DLS, AFM, and XPS. Fluorescence spectrum showed a quantum yield of 0.25 while Raman spectroscopy showed rapid amplification of CND specific peaks implicating significant SERS property. Further in vitro biocompatibility (MTT) and bio-imaging capability was assessed culturing Wharton's Jelly-derived MSCs. In this study, its efficacy as in-situ cellular oxidative stress scavenger is also studied using NBT and DCFH-DA assay. Via ALP assay, alizarin red staining, cell membrane nanoindentation studies, PCR analysis and immunocytochemistry for osteoblast-like gene expression it was confirmed that AgCs can control silver nanoparticle-induced inhibition of osteogenic differentiation in vitro. Thus, AgCs (Carbon nanodots supported silver clusters) are not only considered to be a dual-mode bio-imaging nanoprobe but also a remedy to the silver-induced ROS generation and osteogenic differentiation blockade of MSCs.

Carbon Nanodots Doped Super-paramagnetic Iron Oxide Nanoparticles for Multimodal Bioimaging and Osteochondral Tissue Regeneration via External Magnetic Actuation.

Super-paramagnetic iron oxide nanoparticles (SPIONs) have multiple theranostics applications such as T2 contrast agent in magnetic resonance imaging (MRI) and electromagnetic manipulations in biomedical devices, sensors, and regenerative medicines. However, SPIONs suffer from the limitation of free radical generation, and this has a certain limitation in its applicability in tissue imaging and regeneration applications. In the current study, we developed a simple hydrothermal method to prepare carbon quantum dots (CD) doped SPIONs (FeCD) from easily available precursors. The nanoparticles are observed to be cytocompatible, hemocompatible, and capable of scavenging free radicals in vitro. They also have been observed to be useful for bimodal imaging (fluorescence and MRI). Further, 3D printed gelatin-FeCD nanocomposite nanoparticles were prepared and used for tissue engineering using static magnetic actuation. Wharton's jelly derived mesenchymal stem cells (MSCs) were cultured on them with magnetic actuation and implanted at the subcutaneous region. The tissues obtained have shown features of both osteogenic and chondrogenic differentiation of the stem cells in vivo. In vitro, PCR studies show MSCs express gene expression of both bone and cartilage-specific markers, suggesting FeCDs under magnetic actuation can lead MSCs to go through differentiating into an endochondral ossification route.

In Vivo Cell Tracking, Reactive Oxygen Species Scavenging, and Antioxidative Gene Down Regulation by Long-Term Exposure of Biomass-Derived Carbon Dots.

Biomass derived carbon dots (CD) have been observed to be excellent bioimaging probes due to their nontoxic, stable fluorescence, lesser bleachability, and excellent bioconjugation properties. In the current study, green chili extract derived CD synthesis via microwave irradiation is reported. The time dependent top down degradation of carbonaceous materials to CD are monitored via electron microscopy and correlated with fluorescence intensity. Further, the CD were explored for long-term cell tracking and cell therapy monitoring in a rodent model to study wound healing kinetics. The cells were monitorable up to 21 days (until the entire wound healed). CD were observed to scavenge reactive oxygen species (ROS) in vitro and in vivo and provided control over ROS scavenging enzyme gene expressions via down regulation. Further, it was observed to remodel the wound healing kinetics via altering granulation tissue distribution and formation of microvessels to establish the capability of CD to enhance wound healing.

Morphology-induced physico-mechanical and biological characteristics of TPU-PDMS blend scaffolds for skin tissue engineering applications.

Composition and architecture of scaffolds are the most important factors determining the performance of skin substitutes. In this work, morphology induced unique physical and biological characteristics of compatibilized TPU-PDMS blend scaffolds at 90:10, 80:20, and 70:30 blend ratios of TPU and PDMS was studied. The fiber morphology, porosity, surface wettability, and mechanical properties of electrospun scaffolds were distinctly influenced by the presence of PDMS. Interestingly, the scaffold architecture varied from electrospun fibers to porous fibers and finally occurrence of unique porous beads noticed at 30% PDMS in the microstructure which was confirmed using FESEM. Micro-CT analysis revealed that the porosity of electrospun scaffolds was enhanced from 61% to 79% with 30 parts of PDMS addition. Moreover, MTT assay and cell proliferation were studied using human skin fibroblast cells and found to be significantly enhanced with the PDMS percentage. TPU-PDMS blends offer better overall performance at 70:30 blend ratio of TPU and PDMS (T70P30). Only 4% of hemolysis was observed for T70P30 blends, which establishes the hemocompatibility of the material. In comparison, the results reveal the potential of the cytocompatible T70P30 scaffold for the fabrication of skin substitutes for tissue engineering applications. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 1634-1644, 2019.

Core-Shell Nanofibrous Scaffold Based on Polycaprolactone-Silk Fibroin Emulsion Electrospinning for Tissue Engineering Applications.

The vast domain of regenerative medicine comprises complex interactions between specific cells' extracellular matrix (ECM) towards intracellular matrix formation, its secretion, and modulation of tissue as a whole. In this domain, engineering scaffold utilizing biomaterials along with cells towards formation of living tissues is of immense importance especially for bridging the existing gap of late; nanostructures are offering promising capability of mechano-biological response needed for tissue regeneration. Materials are selected for scaffold fabrication by considering both the mechanical integrity and bioactivity cues they offer. Herein, polycaprolactone (PCL) (biodegradable polyester) and 'nature's wonder' biopolymer silk fibroin (SF) are explored in judicious combinations of emulsion electrospinning rather than conventional electrospinning of polymer blends. The water in oil (W/O) emulsions' stability is found to be dependent upon the concentration of SF (aqueous phase) dispersed in the PCL solution (organic continuous phase). The spinnability of the emulsions is more dependent upon the viscosity of the solution, dominated by the molecular weight of PCL and its concentration than the conductivity. The nanofibers exhibited distinct core-shell structure with better cytocompatibility and cellular growth with the incorporation of the silk fibroin biopolymer.

Bilayered nanofibrous 3D hierarchy as skin rudiment by emulsion electrospinning for burn wound management.

Mimicking skin extracellular matrix hierarchy, the present work aims to develop a bilayer skin graft comprising a porous cotton-wool-like 3D layer with membranous structure of PCL-chitosan nanofibers. Emulsion electrospinning with differential stirring periods of PCL-chitosan emulsion results in development of a bilayer 3D structure with varied morphology. The electrospun membrane has fiber diameter ∼274 nm and pore size ∼1.16 µm while fluffy 3D layer has fiber diameter ∼1.62 µm and pore size ∼62 µm. The 3D layer was further coated with collagen I isolated from Cirrhinus cirrhosus fish scales to improve biofunctionality. Surface coating with collagen I resulted in bundling the fibers together, thereby increasing their average diameter to 2.80 µm and decreasing pore size to ∼45 µm. The architecture and composition of the scaffold promotes efficient cellular activity where interconnected porosity with ECM resembling collagen I coating assists cellular adhesion, infiltration, and proliferation from initial days of fibroblast seeding, while keratinocytes migrate on the surface only without infiltrating in the membranous nanofiber layer. Anatomy of the scaffold arising due to variation in pore size distribution at different layers thereby facilitates compartmentalization and prevents initial cellular transmigration. The scaffold also assists in extracellular matrix protein synthesis and keratinocyte stratification in vitro. Further, the scaffold effectively integrates and attaches with third-degree burn wound margins created in rat models and accelerates healing in comparison to standard Tegaderm dressing™. The bilayer scaffold is thus a promising, readily available, cost-effective, off-the-shelf matrix as a skin substitute.

Onion derived carbon nanodots for live cell imaging and accelerated skin wound healing.

Nitrogen, sulfur, and phosphorous co-doped water-soluble carbon nanodots are synthesized from culinary waste onion peel powder (OPP) by a short microwave treatment. Onion Derived Carbon Nano Dots (OCND) that comprised hydrophilic group-decorated amorphous nano-dots exhibited bright, stable fluorescence at an excitation of 450 nm and emission wavelength at 520 nm along with a free radical scavenging property. The OCND exhibited excellent stability at different pH and UV exposure. Although extracted polyphenols degraded in the extract, interestingly it was shown to be cytocompatible and blood compatible as observed during cytotoxicity, fluorescence imaging of the cell and a hemolysis study. The present work not only focuses on the synthesis of OCND from the OPP extract but also provides an interesting fact that, even after the degradation of polyphenols in the extract, they are non-toxic to human cells (HFF & MG63) and RBCs. Moreover, OCND had no adverse effect on the migration rate of Human Foreskin-derived Fibroblasts (HFFs) as observed from a scratch assay. In addition to accelerating the migration rate of fibroblasts, the OCND altered intra- and extracellular reactive oxygen species (ROS) by enhancing the antioxidant mechanism of a fibroblast under oxidative stress. Further, OCND was observed to accelerate wound healing in a full thickness (FT) wound in a rat model for topical application, which can be attributed to its radical scavenging potential. In summary, this study leads to a new type of OCND synthesis route, which is inherently co-doped with phosphorous, sulfur and nitrogen and holds a great promise for a myriad of biological applications, including bio-imaging, free radical scavenging and wound healing.

Carbon nanodot impregnated fluorescent nanofibers for in vivo monitoring and accelerating full-thickness wound healing.

Semiconductor quantum dots are overwhelmingly used for in situ monitoring and imaging of cell-scaffold interactions. However, quantum dots suffer from oxidative biodegradation in biological systems, besides being toxic due to the presence of heavy metals. In this study, we report the development of an intrinsically fluorescent nanofibrous scaffold of polycaprolactone-gelatin for skin tissue regeneration and noninvasive monitoring of scaffold activity in vivo. The presence of the incorporated carbon nanodots played a critical role in imparting the scaffold with these novel characteristics. The developed scaffold was uniform and bead free with fiber diameter of 698 ± 420 nm and pore diameter of 2.93 ± 1.13 µm. Inclusion of carbon nanodots not only bestowed uniform fluorescence of the scaffold but also promoted fibroblast cell adhesion, migration and proliferation. Co-culture of fibroblast and keratinocyte cells on the scaffold surface also enabled the development of a stratified epithelial layer. The scaffold exhibited antioxidant properties by scavenging free radicals and reducing the expression of antioxidative enzymes. Upon implantation in a full-thickness excision wound, the scaffold accelerated the progression of healing and the regenerated skin exhibited a stratified epithelial layer with mature dermal tissue. The scaffold enabled noninvasive monitoring of the wound healing kinetics in vivo through two-photon microscopy. With excellent photoluminescence, biocompatibility, and photo stability, the scaffold can suitably be used for prolonged monitoring of cell-scaffold interactions and further efficiently reduce the oxidative stress during continuous imaging. Additionally, being synthesized from inexpensive precursors employing a simple procedure, carbon nanodot production is cost-effective and the developed scaffold would be an off-the-shelf, readily available economical product.

Nano-/Microfibrous Cotton-Wool-Like 3D Scaffold with Core-Shell Architecture by Emulsion Electrospinning for Skin Tissue Regeneration.

Electrospun nanofibrous scaffold has long been studied as skin substitutes for their structural resemblance to the dermal extracellular matrix. However, packed fibrous architecture with small pore size restricts cellular infiltration into nanofibrous mat. In this article, we report highly porous, nano-/microfibrous 3D structure using polycaprolactone-chitosan emulsion and its application in skin regeneration. Under the influence of electric field, the emulsion containing encapsulated charged chitosan droplets enhances charge of the spinning solution and residual charge in the core of the deposited fiber, thereby creating core-shell, cotton-like fluffy structure with average pore size 62 µm, fiber diameter ∼1.62 µm, contact angle of 72° and 80% water uptake capacity of the scaffold. Further, differential stirring period of the specific emulsion developed compact nanofibrous membrane with nanometer ranged pore size emphasizing the role played by emulsion droplet size and the charge carried thereafter. Presence of nanofibers with high-interconnected porosity promoted efficient cellular infiltration and proliferation from initial days of cell seeding. The scaffold supported extracellular matrix protein expression and stratified epithelialization in vitro. Effective integration and attachment of scaffold with margins of a full-thickness excision wound created in a rat model with accelerated healing within 3 weeks proved the efficiency of the scaffold as skin substitute. Additionally, gradual and prolong release of acidic chitosan from the core section benefitted wound healing by lowering the pH of wound environment. Simple technique with inexpensive raw materials endorsed the scaffold as a promising off-the-shelf matrix for skin tissue regeneration.

Accelerating full thickness wound healing using collagen sponge of mrigal fish (Cirrhinus cirrhosus) scale origin.

The potentiality of collagen sponge as a skin substitute, derived from mrigal (Cirrhinus cirrhosus) scale has been explored in this study. Acid soluble collagen (ASC) and pepsin soluble collagen (PSC) from the scale of mrigal were isolated and characterized. The yields of ASC and PSC were ∼3% and ∼7% based on the dry weight of scale while the hydroxyproline content was ∼90mg/g. Scanning electron microscope revealed progressive demineralization with EDTA on time dependent scale. Further, the D-Spacing in fibril bundles were calculated to be ∼67nm. Fourier transform infrared and circular dichroism spectra confirmed extracted protein to be collagen I, where both ASC and PSC comprised of two different α-chains (α1 and α2). The denaturation temperature (Td) of the collagen solution was 35°C closer to Td of mammalian collagen. In vitro cell culture studies on the extracted collagen sponge showed efficient cell growth and proliferation. Additionally, co-culture with fibroblast and keratinocyte cells showed development of stratified epidermal layer in vitro. Faster wound healing potential of the extracted collagen in a rat model proved its applicability as a dermal substitute.