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According to the CDC, the rate of total knee replacement has increased by 86% for men and 99% for women aged 45 and over from 2000-2015.1 Successful healing of tissues and integration of implants requires that the surfaces of implants resist bacterial biofilm formation. Therefore, there is a need to develop implant surfaces that prevent infection. Surface modifications that introduce favorable chemistries and nanotopography can enhance osseointegration and reduce complications. Carrageenan and its derivatives are natural, attractive biomaterials which have exhibit no cytotoxicity, high cell viability and bacterial inhibition.2 Modification of carrageenans through caboxymethylation and amination can enhance the biological properties of carrageenans to improve biological outcomes. 

The integration of nano-structural properties of titania nanotube (TiNT) with the versatile properties of the biopolymer tanfloc has the potential to enhance the biocompatibility of titania surfaces. This study demonstrates the behavior of the blood components and human adipose-derived stem cells (ADSC) on the TiNT surface functionalized by covalent conjugation of tanfloc (TiNT-TAN). The results demonstrate that TiNT-TAN has great potential to control protein adsorption and platelet adherence. The zwitterionic nature and multiple organic functional groups on tanfloc can control blood protein adsorption, platelet adherence, and activation. It provides a compatible surface for cell attachment and growth without any cytotoxic effect. 

Abstract Owing to significant differences across species in liver functions, in vitro human liver models are used for screening the metabolism and toxicity of compounds, modeling diseases, and cell‐based therapies. However, the extracellular matrix (ECM) scaffold used for such models often does not mimic either the complex composition or the nanofibrous topography of native liver ECM. Thus, here novel methods are developed to electrospin decellularized porcine liver ECM (PLECM) and collagen I into nano‐ and microfibers (≈200–1000 nm) without synthetic polymer blends. Primary human hepatocytes (PHHs) on nanofibers in monoculture or in coculture with nonparenchymal cells (3T3‐J2 embryonic fibroblasts or primary human liver endothelial cells) display higher albumin secretion, urea synthesis, and cytochrome‐P450 1A2, 2A6, 2C9, and 3A4 enzyme activities than on conventionally adsorbed ECM controls. PHH functions are highest on the collagen/PLECM blended nanofibers (up to 34‐fold higher CYP3A4 activity relative to adsorbed ECM) for nearly 7 weeks in the presence of the fibroblasts. In conclusion, it is shown for the first time that ECM composition and topography synergize to enhance and stabilize PHH functions for several weeks in vitro. The nanofiber platform can prove useful for the above applications and to elucidate cell‐ECM interactions in the human liver. 

Drug-induced liver injury (DILI) remains a leading cause of drug attrition and acute liver failures, partly due to the inadequacy of animal models to accurately predict human clinical outcomes, which necessitates the utilization of in vitro models of the human liver. However, primary human hepatocytes (PHHs) are in short supply for routine drug screening. In contrast, induced pluripotent stem cells (iPSCs)-derived hepatocyte-like cells (HLCs) are a nearly unlimited cell source but display a fetal-like (versus adult-like) phenotype when differentiated using conventional protocols on tissue culture plastic or glass adsorbed with 2D extracellular matrix (ECM) proteins. Electrospinning can produce porous nanoscale 3D fibers that have a large surface area and present a high density of receptor ligands to modulate cell phenotype. However, the application of electrospinning to generate 3D liver-derived ECM substrates for HLC differentiation remains unexplored. Therefore, here we developed methods to a) electrospin nanofibers of different porosities and diameters using porcine liver ECM (PLECM) with or without type I collagen and b) use these fibers to determine functional modulation in iPSC-derived HLCs while using PHHs as a control cell type relative to conventional adsorbed ECM substrates.