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Osteoarthritis (OA) is one of the most common chronic musculoskeletal diseases, which accounts for a large proportion of physical disabilities worldwide. Herein, we fabricated injectable gelatin/poly(L-lactide)-based nanofibrous microspheres (MS) via electrospraying technology, which were further modified with tannic acid (TA) named as TMS or metal phenolic networks (MPNs) consisting of TA and strontium ions (Sr2+) and named as TSMS to enhance their bioactivity for OA therapy. The TA-modified microspheres exhibited stable porous structure and anti-oxidative activity. Notably, TSMS showed a sustained release of TA as compared to TMS, which exhibited a burst release of TA. While all types of microspheres exhibited good cytocompatibility, TSMS displayed good anti-inflammatory properties with higher cell viability and cartilage-related extracellular matrix (ECM) secretion. The TSMS microspheres also showed less apoptosis of chondrocytes in the hydrogen peroxide (H 2 O 2)-induced inflammatory environment. The TSMS also inhibited the degradation of cartilage along with the considerable repair outcome in the papain-induced OA rabbit model in vivo as well as suppressed the expression level of inflammatory cytokines, such as tumor necrosis factor-alpha (TNF-α) and interleukin-1-beta (IL-1β). Taken together, TSMS may provide a highly desirable therapeutic option for intra-articular treatment of OA. Osteoarthritis (OA) is a chronic disease, which is caused by the inflammation of joint. Current treatments for OA achieve pain relief but hardly prevent or slow down the disease progression. Microspheres are at the forefront of drug delivery and tissue engineering applications, which can also be minimal-invasively injected into the joint. Polyphenols and therapeutic ions have been shown to be beneficial for the treatment of diseases related to the joints, including OA. Herein, we prepared gelatin/poly(L-lactide)-based nanofibrous microspheres (MS) via electrospinning incorporated electrospraying technology and functionalized them with the metal phenolic networks (MPNs) consisting of TA and strontium ions (Sr2+), and assessed their potential for OA therapy both in vitro and in vivo. [Display omitted] [ABSTRACT FROM AUTHOR]

Massive hemorrhage may be detrimental to the patients, which necessitates the advent of new materials with high hemostatic efficiency and good biocompatibility. The objective of this research was to screen for the effect of the different types of bio-elastomers as hemostatic dressings. 3D loose nanofiber sponges were prepared; PU-TA/Gel showed promising potential. Polyurethane (PU) was synthesized and electrospun to afford porous sponges, which were crosslinked with glutaraldehyde (GA). FTIR and 1H-NMR evidenced the successful synthesis of PU. The prepared PU-TA/Gel sponge had the highest porosity and water absorption ratio. Besides, PU-TA/Gel sponges exhibited cytocompatibility, negligible hemolysis and the shortest clotting time. PU-TA/Gel sponge rapidly induced stable blood clots with shorter hemostasis time and less bleeding volume in a liver injury model in rats. Intriguingly, PU-TA/Gel sponges also induced good skin regeneration in a full-thickness excisional defect model as revealed by the histological analysis. These results showed that the PU-TA/Gel-based sponges may offer an alternative platform for hemostasis and wound healing. [ABSTRACT FROM AUTHOR]

Tissue engineering (TE) has attracted the widespread attention of the research community as a method of producing patient-specific tissue constructs for the repair and replacement of injured tissues. To date, different types of scaffold materials have been developed for various tissues and organs. The choice of scaffold material should take into consideration whether the mechanical properties, biodegradability, biocompatibility, and bioresorbability meet the physiological properties of the tissues. Owing to their broad range of physico-chemical properties, inorganic materials can induce a series of biological responses as scaffold fillers, which render them a good alternative to scaffold materials for tissue engineering (TE). While it is of worth to further explore mechanistic insight into the use of inorganic nanomaterials for tissue repair, in this review, we mainly focused on the utilization forms and strategies for fabricating electrospun membranes containing inorganic components based on electrospinning technology. A particular emphasis has been placed on the biological advantages of incorporating inorganic materials along with organic materials as scaffold constituents for tissue repair. As well as widely exploited natural and synthetic polymers, inorganic nanomaterials offer an enticing platform to further modulate the properties of composite scaffolds, which may help further broaden the application prospect of scaffolds for TE. [ABSTRACT FROM AUTHOR]

Ligament injuries are common in sports and other rigorous activities. It is a great challenge to achieve ligament regeneration after an injury due the avascular structure and low self-renewal capability. Herein, we developed vascular endothelial growth factor (VEGF)-binding aligned electrospun poly(caprolactone)/gelatin (PCL/Gel) scaffolds by incorporating prominin-1-binding peptide (BP) sequence and exploited them for patellar ligament regeneration. The adsorption of BP onto scaffolds was discerned by various techniques, such as Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, and confocal laser scanning microscope. The accumulation of VEGF onto scaffolds correlated with the concentration of the peptide in vitro. BP-anchored PCL/Gel scaffolds (BP@PCL/Gel) promoted the tubular formation of human umbilical vein endothelial cells (HUVECs) and wound healing in vitro. Besides, BP containing scaffolds exhibited higher content of CD31+ cells than that of the control scaffolds at 1 week after implantation in vivo. Moreover, BP containing scaffolds improved biomechanical properties and facilitated the regeneration of matured collagen in patellar ligament 4 weeks after implantation in mice. Overall, this strategy of peptide-mediated orchestration of VEGF provides an enticing platform for the ligament regeneration, which may also have broad implications for tissue repair applications. Ligament injuries are central to sports and other rigorous activities. Given to the avascular nature and poor self-healing capability of injured ligament tissues, it is a burgeoning challenge to fabricate tissue-engineered scaffolds for ligament reconstruction. Vascular endothelial growth factor (VEGF) is pivotal to the neo-vessel formation. However, the high molecular weight of VEGF as well as its short half-life in vitro and in vivo limits its therapeutic potential. To circumvent these limitations, herein, we functionalized aligned electrospun polycaprolactone/gelatin (PCL/Gel)-based scaffolds with VEGF-binding peptide (BP) and assessed their biocompatibility and performance in vitro and in vivo. BP-modified scaffolds accumulated VEGF, improved tube formation of HUVECs, and induced wound healing in vitro , which may have broad implications for regenerative medicine and tissue engineering. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] Multifunctional bioactive biomaterials with integrated bone and soft tissue regenerability hold great promise for the regeneration of trauma-affected skin and bone defects. The aim of this research was to fabricate aerogel scaffolds (GD-BF) by blending the appropriate proportions of short bioactive glass fiber (BGF), gelatin (Gel), and dopamine (DA). Electrospun polyvinyl pyrrolidone (PVP)-BGF fibers were converted into short BGF through calcination and homogenization. Microporous GD-BF scaffolds displayed good elastic deformation recovery and promoted neo-tissue formation. The DA could enable thermal crosslinking and enhance the mechanical properties and structural stability of the GD-BF scaffolds. The BGF-mediated release of therapeutic ions shorten hemostatic time (<30 s) in a rat tail amputation model and a rabbit artery injury model alongside inducing the regeneration of skin appendages (e.g., blood vessels, glands, etc.) in a full-thickness excisional defect model in rats (percentage wound closure: GD-BF2, 98 % vs. control group, 83 %) at day 14 in vitro. Taken together, these aerogel scaffolds may have significant promise for soft and hard tissue repair, which may also be worthy for the other related disciplines. [ABSTRACT FROM AUTHOR]

[Display omitted] • VEGF-binding peptide "BP" and OEO were loaded into PLGA/Gelatin fibers. • OEO improved anti-inflammatory, anti-oxidative, and anti-bacterial properties. • The BP containing fibers effectively accelerated angiogenesis. • BP and OEO co-loaded fibers showed rapid repair of infected wounds. • Combined delivery of BP and OEO also suppress bacterial growth in vivo. Skin regeneration is hindered by poor vascularization, bacterial infection, prolonged inflammation, and oxidative wound microenvironment, which necessitate the fabrication of alternative wound dressings with anti-adhesion, anti-infection, and angiogenic functions. Prominin-1-derived peptide (PR1P, herein named as BP) may sequester vascular endothelial growth factor (VEGF) by interacting with VEGF receptors and promote wound healing. Oregano essential oil (OEO, herein named as O), is a natural plant extract mainly containing carvacrol and thymol, which manifests low cytotoxicity and cost-effectiveness as well as anti-inflammatory, antibacterial, and anti-oxidative properties. Herein, we fabricated anti-adhesion, anti-infection, and angiogenic wound dressings by simultaneously exploiting BP and O in electrospun poly(L-lactide-co-glycolide)/gelatin (PG)-based fibrous dressings. Different types of in vitro assays manifested anti-inflammatory, anti-oxidative, anti-bacterial, and angiogenic characteristics of dressings. The PG@BPO dressings further enabled good wound healing 14 days post-implantation alongside anti-adhesion, and anti-infection properties. The tensile strength of the repaired skin was almost similar to the normal skin (repaired skin, 1.70 MPa and normal skin, 1.78 MPa). These multifunctional dressings may hold great promise for skin repair and related disciplines. [ABSTRACT FROM AUTHOR]

Cardiovascular diseases cause huge socio-economic burden worldwide. Although a mammalian myocardium has its own limited healing capability, scaffold materials capable of releasing stem cell recruiting/engrafting factors may facilitate the regeneration of the infarcted myocardium. The aim of this research was to develop cardiac patches capable of simultaneously eluting substance P (SP) and insulin-like growth factor-1C (IGF-1C) peptide. Polycaprolactone/collagen type 1-based patches with or without SP and IGF-1C peptide were fabricated by co-electrospinning, which exhibited nanofibrous morphology. SP and IGF-1C/SP patches recruited significantly higher numbers of bone marrow-mesenchymal stem cells than that of the negative control and patch-only groups in vitro. The developed patches were transplanted in an infarcted myocardium for up to 14 days. Mice underwent left anterior descending artery ligation and received one of the following treatments: (i) sham, (ii) saline, (iii) patch-only, (iv) IGF-1C patch, (v) SP patch and (vi) IGF-1C/SP patch. SP and IGF-1C/SP patch-treated groups exhibited better heart function and attenuated adverse cardiac remodeling than that of the saline, patch-only and individual peptide containing cardiac patches. SP patch and IGF-1C/SP patch-treated groups also showed higher numbers of CD31- positive vessels and isolectin B4-positive capillaries than that of other groups. IGF-1C/SP-treated group also showed thicker left ventricular wall in comparison to the saline and patch-only groups. Moreover, IGF-1C/SP patches recruited significantly higher numbers of CD29-positive cells and showed less numbers of Tunel-positive cells compared with the other groups. These data suggest that SP and IGF-1C peptides may act synergistically for in situ tissue repair. [ABSTRACT FROM AUTHOR]

Skin regeneration is hindered by poor vascularization, prolonged inflammation, and excessive scar tissue formation, which necessitate newer strategies to simultaneously induce blood vessel regeneration, resolve inflammation, and induce host cell recruitment. Concurrent deployment of multiple biological cues to realize synergistic reparative effects may be an enticing avenue for wound healing. Herein, we simultaneously deployed SDF (stromal cell-derived factor)− 1α, VEGF (vascular endothelial growth factor)-binding peptide (BP), and GLP (glucagon like peptide)− 1 analog, liraglutide (LG) in core/shell poly(L -lactide-co-glycolide)/gelatin fibers to harness their synergistic effects for skin repair in healthy as well as diabetic wound models in rats. Microscopic techniques, such as SEM and TEM revealed fibrous and core/shell type morphology of membranes. Boyden chamber assay and scratch-wound assay displayed significant migration of HUVECs (human umbilical vein endothelial cells) in SDF-1α containing fibers. Subcutaneous implantation of membranes revealed higher cellular infiltration in SDF-1α loaded fibers, especially, those which were co-loaded with LG or BP. Implantation of membranes in an excisional wound model in healthy rats further showed significant and rapid wound closure in dual cues loaded groups as compared to control or single cue loaded groups. Similarly, the implantation of dressings in type 2 diabetes rat model revealed fast healing, skin appendages regeneration, and blood vessel regeneration in dual cues loaded fibers (SDF-1α/LG, SDF-1α/BP). Taken together, core/shell type fibers containing bioactive peptides significantly promoted wound repair in healthy as well as diabetic wound models in rats. [Display omitted] • Core/shell electrospun PLGA/gelatin fibers were developed for skin repair. • SDF-1α, liraglutide (LG) and VEGF-binding peptide (BP) were loaded into fibers' core. • SDF-1α loaded fibers showed significant migration of HUVECs in vitro. • Dual cues-loaded fibers showed higher cellularization in subcutaneous implantation. • SDF-1α/LG and SDF-1α/BP exhibited significant healing in healthy and diabetic models. [ABSTRACT FROM AUTHOR]

We investigated the adsorption of lead (Pb2+) and nickel (Ni2+) ions by electrospun membranes of polyacrylonitrile (PAN) nanofiber activated with NaHCO3 (PANmod). Analysis by Fourier-transform infrared spectrometry (FTIR), field emission scanning electron microscopy (FE-SEM), and energy dispersive X-ray spectroscopy (EDX) validated the functionalization of PAN nanofibers with NaHCO3, and the successful agglomeration of Pb2+ and Ni2+ onto PANmod. After a rapid uptake of the heavy metal ions (15 min), the equilibrium contact time was attained (60 min) following a linear increase of both adsorption capacity and removal efficiency. PANmod showed a better affinity for Ni2+ than Pb2+. The adsorption on PANmod was best described by the pseudo-second-order kinetic model for both studied models, supporting chemisorption. By varying the solution pH from 2.0 to 9.0, we found that the adsorption capacity followed an increasing trend, reaching a maximum at the pH of 7.0. Despite increasing adsorption capacities, the removal efficiency of both heavy metal ions exhibited a decreasing trend with increase in initial concentrations. The amount of PANmod directly affects the removal efficiency, with 0.7 and 0.2 g being the optimum dose for maximum uptake of Pb2+ and Ni2+, respectively. The Langmuir model fitted well the Pb2+ adsorption data suggesting monolayer adsorption, and the Freundlich model perfectly fitted the Ni2+ adsorption data, indicating heterogeneous adsorption. The estimated values of the mean free energy of adsorption in the D–R isotherm indicated a physical adsorption of both heavy metal ions into the surface of the PANmod. [ABSTRACT FROM AUTHOR]

Cardiovascular injuries cause huge morbidity and mortality worldwide. Arterial reconstructions are generally performed either by using native grafts or synthetic grafts, both of which are limited by several complications. Synthetic biodegradable polymers offer a promising platform, which may also be modified to foster in situ tissue regeneration through the recruitment of host cells. Vascular endothelial growth factor (VEGF) promotes endothelialization and neovascularization in vascular grafts, however, an overdose of VEGF may induce tumor-like vasculature, which requires alternative strategies. The objective of this study was to exploit prominin-1-derived VEGF-binding peptide (BP) to improve neovascularization and endothelialization, while stromal cell-derived factor 1-alpha (SDF-1α) peptide to encourage endogenous stem/progenitor cells mobilization and complement BP-mediated vascular remodeling. The BP and SDF-1α peptides were covalently conjugated with low molecular weight poly (ε-caprolactone) (LPCL) to afford LPCL-BP and LPCL-SDF-1α, respectively. Chemical analysis revealed successful modification of LPCL with peptides, which also displayed good cytocompatibility in vitro once blended along with high molecular weight PCL (HPCL). The bioactived vascular grafts were fabricated by blending LPCL-BP, LPCL-SDF-1α or dual peptide-polymer conjugates with HPCL. The in vivo tests of vascular grafts through rat abdominal aorta implantation model revealed that, compared with HPCL grafts, the dual peptides modified grafts exhibited superior patency and tissue regeneration at 4-week post-implantation, including stem cell recruitment, rapid endothelialization and functional SMC layer formation. Taken together, these results may have implications for the in situ regeneration of artificial blood vessels through the orchestration of host's responses and endogenous cell recruitment. [ABSTRACT FROM AUTHOR]