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Osteoarthritis (OA) is one of the most common musculoskeletal disorders worldwide. Oxidative stress initiated by excessive free radicals such as reactive oxygen species (ROS) is a leading cause of cartilage degradation and OA. However, conventional injection or oral intake of antioxidants usually cannot provide effective treatment due to rapid clearance and degradation or low bioavailability. Here, a new strategy is proposed based on nanofibers made of poly (ε-caprolactone) (PCL) and PCL-grafted lignin (PCL-g-lignin) copolymer. Lignin offers intrinsic antioxidant activity while PCL tailors the mechanical properties. Electrospun PCL-lignin nanofibers show excellent antioxidant activity, low cytotoxicity and excellent anti-inflammatory effects as demonstrated using both H 2 O 2 -stimulated human chondrocytes and an OA rabbit model. PCL-lignin nanofibers inhibit ROS generation and activate antioxidant enzymes through autophagic mechanism. Arthroscopic implantation of nanofibrous membrane of PCL-lignin is effective to OA therapy because it is biocompatible, biodegradable and able to provide sustained antioxidant activity., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Cartilage cannot self-repair and thus regeneration is a promising approach to its repair. Here we developed new electrospun nanofibers, made of poly (ε-caprolactone)/polytetrahydrofuran (PCL-PTHF urethane) and collagen I from calf skin (termed PC), to trigger the chondrogenic differentiation of mesenchymal stem cells (MSCs) and the cartilage regeneration in vivo. We found that the PC nanofibers had a modulus (4.3 Mpa) lower than the PCL-PTHF urethane nanofibers without collagen I from calf skin (termed P) (6.8 Mpa) although both values are within the range of the modulus of natural cartilage (1-10 MPa). Both P and PC nanofibers did not show obvious difference in the morphology and size. Surprisingly, in the absence of the additional chondrogenesis inducers, the softer PC nanofibers could induce the chondrogenic differentiation in vitro and cartilage regeneration in vivo more efficiently than the stiffer P nanofibers. Using mRNA-sequence analysis, we found that the PC nanofibers outperformed P nanofibers in inducing chondrogenesis by specifically blocking the NF-kappa B signaling pathway to suppress inflammation. Our work shows that the PC nanofibers can serve as building blocks of new scaffolds for cartilage regeneration and provides new insights on the effect of the mechanical properties of the nanofibers on the cartilage regeneration., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

With advances in the field of tissue engineering, it is increasingly recognized that biodegradable and biocompatible scaffolds incorporated with multiple wound healing mediators might serve as the most promising medical devices for skin tissue regeneration. Through controlled drug delivery, these medical devices can reduce the toxicity effects and optimize clinical efficiency. In this study, we first encapsulated multiple epidermal induction factors (EIF) such as the epidermal growth factor (EGF), insulin, hydrocortisone, and retinoic acid (RA) with gelatin and poly(L-lactic acid)-co-poly-(ε-caprolactone) (PLLCL) solutions and performed electrospinning by two different approaches: blend spinning and core-shell spinning. No burst release was detected from EIF encapsulated core-shell nanofibers; however, an initial 44.9% burst release from EIF blended nanofibers was observed over a period of 15 days. The epidermal differentiation potential of adipose-derived stem cells (ADSCs) was evaluated for EIF-containing scaffolds prepared either by core-shell spinning or by blend spinning. After 15 days of cell culture, the proliferation of ADSCs on EIF encapsulated core-shell nanofibers was the highest. Moreover, a higher percentage of ADSCs got differentiated to epidermal lineages on EIF encapsulated core-shell nanofibers compared to the cell differentiation on EIF blended nanofibers, which can be attributed to the sustained release of EIF from the core-shell nanofibers. Our study demonstrated that the EIF encapsulated core-shell nanofibers might serve as a promising tissue engineered graft for skin regeneration., (Copyright © 2013 Elsevier B.V. All rights reserved.)

Use of plant extracts for treatment of burns and wound is a common practice followed over the decades and it is an important aspect of health management. Many medicinal plants have a long history of curative properties in wound healing. Electrospun nanofibers provide high porosity with large surface area-to-volume ratio and are more appropriate for cell accommodation, nutrition infiltration, gas exchange and waste excretion. Electrospinning makes it possible to combine the advantages of utilizing these plant extracts in the form of nanofibrous mats to serve as skin graft substitutes. In this study, we investigated the potential of electrospinning four different plant extracts, namely Indigofera aspalathoides, Azadirachta indica, Memecylon edule (ME) and Myristica andamanica along with a biodegradable polymer, polycaprolactone (PCL) for skin tissue engineering. The ability of human dermal fibroblasts (HDF) to proliferate on the electrospun nanofibrous scaffolds was evaluated via cell proliferation assay. HDF proliferation on PCL/ME nanofibers was found the highest among all the other electrospun nanofibrous scaffolds and it was 31% higher than the proliferation on PCL nanofibers after 9 days of cell culture. The interaction of HDF with the electrospun scaffold was studied by F-actin and collagen staining studies. The results confirmed that PCL/ME had the least cytotoxicity among the different plant extract containing scaffolds studied here. Therefore we performed the epidermal differentiation of adipose derived stem cells on PCL/ME scaffolds and obtained early and intermediate stages of epidermal differentiation. Our studies demonstrate the potential of electrospun PCL/ME nanofibers as substrates for skin tissue engineering., (Copyright © 2012 Elsevier Ltd. All rights reserved.)