a b s t r a c tDelivering hydrophobic drug within hydrophilic polymer matrix as carrier is usually a challenge. Here we report the synthesis of gelatin nanofibers by electrospinning, followed by testing them as a potential carrier for oral drug delivery system for a model hydrophobic drug, piperine. Electrospun gelatin nanofibers were crosslinked by exposing to saturated glutaraldehyde (GTA) vapor, to improve their water resistive properties. An exposure of only 6 min was not only adequate to control the early degradation with intact fiber morphology, but also significantly marginalized any adverse effects associated with the use of GTA. Scanning electron microscopy imaging, Fourier transform infrared spectroscopy and thermogravimetric analysis were done to study nanofiber morphology, stability of drug and effect of crosslinking. The pH of release medium was also varied as per the gastrointestinal tract for in-vitro drug release study. Results illustrate good compatibility of hydrophobic drug in gelatin nanofibers with promising controlled drug release patterns by varying crosslinking time and pH of release medium.

In this work, we report a low‐cost, less energy intensive, and an innovative way of recycling thermoplastic polystyrene (PS) waste objects into submicron, aligned fibers using extract from citrus peel, an agricultural waste. As‐fabricated recycled PS fabric is then structurally characterized and tested as an oil sorbent material. The hydrophobic‐oleophilic PS fabric is found to absorb 40.5 ± 3.6 g/g of oil, with 77.3% oil retention within 1 h. To investigate the practical application of recycled PS fabric for oil spills remediation, we tested its buoyancy properties in oil‐over‐water static and dynamic system besides examining their reusability. The as‐fabricated fabric floats on water after oil sorption indicating its high buoyancy and therefore can be collected easily after soaking the oil. This work is a simple illustration of systematic analysis of recycling two different waste materials (thermoplastic polystyrene and citrus peels) and reusing them into a more valuable product. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47886.

No abstract

The investigation is focused on the development of a compartmentalized microfluidic device for coculturing the cells of crucial retinal cellular layers and assessing cellto-cell interactions. A perfusion-based microfluidic co-culture device was employed and computationally validated for determining the pressure drop and fluid flow rate within the device microchannels. Fabrication was performed using PDMS polymer and coating of fibronectin and collagen facilitated adherence of the cells over the glass surface. Microfluidic device successfully supported cell proliferation, under continuous perfusion of 1 μl min -1 flow rate. The barrier integrity of this coculture was confirmed by evaluating the permeability of fluorescently labeled molecules. The coculture expressed characteristic phenotypic protein markers like recoverin, PAX6, for retinal precursor cells, and RPE65 for retinal epithelial cells. The coculture also exhibited basal expression of TNF-α under normal conditions. Differentiated photoreceptor cells positively expressed rhod inherently possess sensitivity toward violet/blue light, which was validated in R28 cells by exposure to light having a wavelength of 405 nm, which significantly decreased cell viability via increased TNF-α production and reduced rhodopsin expression. This proof-of-concept investigation proved the functionality of the retinal coculture, which may be used as an appropriate perfusion-based, preclinical tool for the evaluation of novel retinal drugs and delivery systems.

Intricate structures of natural surfaces and materials have amazed people over the ages. The unique properties of various surfaces also created interest and curiosity in researchers. In the recent past, with the advent of superior microscopy techniques, we have started to understand how these complex structures provide superior properties. With that knowledge, scientists have developed various biomimicked and bio-inspired surfaces for different non-biological applications. In the last two decades, we have also started to learn how structures of the tissue microenvironment influence cell function and behaviour, both in physiological and pathological conditions. Hence, it became essential to decipher the role and importance of structural hierarchy in the cellular context. With advances in microfabricated techniques, such complex structures were made by superimposing features of different dimensions. However, the fabricated topographies are far from matching the complexities present in vivo. Hence, the need of biomimicking the natural surfaces for cellular applications was felt. In this review, we discuss a few examples of hierarchical surfaces found in plants, insects, and vertebrates. Such structures have been widely biomimicked for various applications but rarely studied for cell-substrate interaction and cellular response. Here, we discuss the research work wherein 2D hierarchical substrates were prepared using biomimicking to understand cellular functions such as adhesion, orientation, differentiation, and formation of spheroids. Further, we also present the status of ongoing research in mimicking 3D tissue architecture using de-cellularized plant-based and tissue/organ-based scaffolds. We will also discuss 3D printing for fabricating 2D and 3D hierarchical structures. The review will end by highlighting the various advantages and research challenges in this approach. The biomimicked in-vivo like substrate can be used to better understand cellular physiology, and for tissue engineering.