Biocompatible polymer scaffolds are promising as potential carriers for the delivery of retinal progenitor cells (RPCs) in cell replacement therapy for the repair of damaged or diseased retinas. The primary goal of the present study was to investigate the effects of blended electrospun nanofibrous membranes of silk fibroin (SF) and poly(L-lactic acid-co-ε-caprolactone) (PLCL), a novel scaffold, on the biological behaviour of RPCs in vitro. To assess the cell-scaffold interaction, RPCs were cultured on SF/PLCL scaffolds for indicated durations. Our data revealed that all the SF/PLCL scaffolds were thoroughly cytocompatible, and the SF:PLCL (1:1) scaffolds yielded the best RPC growth. The in vitro proliferation assays showed that RPCs proliferated more quickly on the SF:PLCL (1:1) than on the other scaffolds and the control. Quantitative polymerase chain reaction (qPCR) and immunocytochemistry analyses demonstrated that RPCs grown on the SF:PLCL (1:1) scaffolds preferentially differentiated toward retinal neurons, including, most interestingly, photoreceptors. In summary, we demonstrated that the SF:PLCL (1:1) scaffolds can not only markedly promote RPC proliferation with cytocompatibility for RPC growth but also robustly enhance RPCs’ differentiation toward specific retinal neurons of interest in vitro, suggesting that SF:PLCL (1:1) scaffolds may have potential applications in retinal cell replacement therapy in the future.

Background Fat grafting, as a standard treatment for numerous soft tissue defects, remains unpredictable and technique-dependent. Human adipose-derived stem cells (hADSCs) are promising candidates for cell-assisted therapy to improve graft survival. As free-living fat requires nutritional and respiratory sources to thrive, insufficient and unstable vascularization still impedes hADSC-assisted therapy. Recently, cytotherapy combined with modified mRNA (modRNA) encoding vascular endothelial growth factor (VEGF) has been applied for the treatment of ischemia-related diseases. Herein, we hypothesized that VEGF modRNA (modVEGF)-engineered hADSCs could robustly enhance fat survival in a fat graft transplantation model. Methods hADSCs were acquired from lipoaspiration and transfected with modRNAs. Transfection efficiency and expression kinetics of modRNAs in hADSCs were first evaluated in vitro. Next, we applied an in vivo Matrigel plug assay to assess the viability and angiogenic potential of modVEGF-engineered hADSCs at 1 week post-implantation. Finally, modVEGF-engineered hADSCs were co-transplanted with human fat in a murine model to analyze the survival rate, re-vascularization, proliferation, fibrosis, apoptosis, and necrosis of fat grafts over long-term follow-up. Results Transfections of modVEGF in hADSCs were highly tolerable as the modVEGF-engineered hADSCs facilitated burst-like protein production of VEGF in both our in vitro and in vivo models. modVEGF-engineered hADSCs induced increased levels of cellular proliferation and proangiogenesis when compared to untreated hADSCs in both ex vivo and in vivo assays. In a fat graft transplantation model, we provided evidence that modVEGF-engineered hADSCs promote the optimal potency to preserve adipocytes, especially in the long-term post-transplantation phase. Detailed histological analysis of fat grafts harvested at 15, 30, and 90 days following in vivo grafting suggested the release of VEGF protein from modVEGF-engineered hADSCs significantly improved neo-angiogenesis, vascular maturity, and cell proliferation. The modVEGF-engineered hADSCs also significantly mitigated the presence of fibrosis, apoptosis, and necrosis of grafts when compared to the control groups. Moreover, modVEGF-engineered hADSCs promoted graft survival and cell differentiation abilities, which also induced an increase in vessel formation and the number of surviving adipocytes after transplantation. Conclusion This current study demonstrates the employment of modVEGF-engineered hADSCs as an advanced alternative to the clinical treatment involving soft-tissue reconstruction and rejuvenation.

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Purpose: The aim of this study was to compare the ocular microbial communities in humans with and without demodex blepharitis in order to elucidate the relationship between ocular microorganisms and demodex infestation. Methods: Bacterial 16S rRNA genes of conjunctival sac samples from 30 demodex blepharitis patients and 14 healthy controls were sequenced using a pyrosequencing method, and their bacterial community structures were compared by bioinformatics. Results: Bacterial community clustering of conjunctival sac in the demodex blepharitis group were significantly distinct from the healthy control group, with significantly higher relative abundances of Firmicutes and Corynebacterium at the phyla level, as well as higher abundances of Lactobacillus and Bifidobacterium at the genus level. The relative abundance of Staphylococcus epidermidis (0.07–2.27%) was positively correlated with the demodex amount and modified OSDI. The major potential factors contribute to demodex blepharitis were Bacilli, Firmicutes, Cyanobacteria, Lactobacillus and Streptophyta. Conclusions: Patients with demodex blepharitis have varying degrees of bacterial microbiota imbalance in the conjunctival sac. Demodex serving as vectors to transfer both skin and environmental flora might be the potential mechanism. In addition, the number and type of demodex affect the specific ocular surface bacteria, presenting as ocular discomfort and obvious signs of blepharitis.

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Eyelid plays a vital role in protecting the eye from injury or infection. Inflammation related eyelid diseases, such as blepharitis, are the most common ocular disorders that affect human's vision and quality of life. Due to the physiological barriers and anatomical structures of the eye, the bioavailability of topical administrated therapeutics is typically less than 5%. Herein, we developed a bio-responsive hydrogel drug delivery system using a generally recognized as safe compound, triglycerol monostearate (TG-18), for in-situ eyelid injection with sustained therapeutics release. In vitro, drug release and disassembly time of Rosiglitazone loaded hydrogel (Rosi-hydrogel) were estimated in the presence or absence of MMP-9, respectively. Moreover, the disassembly of TG-18 hydrogel was evaluated with 9-month-old and 12-month-old mice in vivo. Owing to the bio-responsive nature of Rosi-hydrogel, the on-demand Rosiglitazone release is achieved in response to local enzymes. These findings are proved by further evaluation in the age-related meibomian gland dysfunction mice model, and the bio-responsive hydrogel is used as an in-situ injection to treat eyelid diseases. Taken together, the in-situ eyelid injection with sustained drug release opens a window for the therapy of inflammation related eyelid diseases.

Corneal endothelial dysfunction involves progressive corneal edema and loss of visual acuity, which result in the need for corneal transplantation. The global shortage of donor corneas limits the development of the surgery. Reconstruction of a bioengineered corneal endothelium might resolve this problem. Various scaffolds have been used, but poor biocompatibility and degradation limit their applications. In this study, a novel method of targeted cellular transplantation without permanent residence of cell carriers in the host was proposed. Human umbilical cord blood endothelial progenitor cells (UCB EPCs) were labeled with CD34 immunomagnetic nanoparticles. The efficiency of the magnet attraction was evaluated in vitro with a simple device simulating the anterior chamber. The UCB EPCs labeled with nanoparticles were transplanted into the anterior chamber of rabbits with magnet attraction. The results indicated that labeling the nanoparticles did not affect the proliferation of the UCB EPCs. The in vitro study indicated that the magnet could directionally attract UCB EPCs labeled with nanoparticles. The in vivo study indicated that the corneas in rabbits transplanted with UCB EPCs labeled with nanoparticles and magnet attraction became relatively transparent with little edema. These results showed that UCB EPCs labeled with CD34 immunomagnetic nanoparticles could be attracted directionally by a magnet and could repair corneal endothelial defects, providing a promising cell therapy for corneal endothelial dysfunction.