Biology subjects

Zha, D.

Publications and source records attributed to Zha, D..

3 recordsLinked to original sources

bioRxiv2025

Coaxially Electrospun Myocardial dECM-based Nanofibrous Scaffolds Demonstrate Enhanced Cardiomyocyte Adhesion and Function

Abstract textLimited regenerative capability of mature cardiomyocytes (CMs) makes myocardial repair more challenging, requiring effective and viable alternatives to conventional heart transplants. Cardiac tissue engineering is a substitutionary approach combining cells, scaffolds, and growth factors to develop functional heart tissues in vitro. Induced pluripotent stem cells (iPSCs) represent a significant advancement in cardiac regenerative medicine, offering a continuous supply of CMs, however, the limited understanding of their microenvironment hinders translational research. Decellularized extracellular matrix (dECM) derived from myocardium is a highly promising natural scaffold for CTE, given its tissue-specific composition, mechanical properties, and biochemical cues that promote cellular regeneration. This study investigates myocardial dECM-based fibrous scaffolds for iPSC-derived CM use. Coaxially electrospun nanofibers comprising a polyurethane core and a blend of polycaprolactone and myocardial dECM as the sheath were optimized. Morphological analysis confirms the resemblance of the nanofibers to fibrillar collagen in the native dECM. ATR-FTIR and immunostaining results confirm the presence of dECM which enhanced their hydrophilicity and enzymatic degradation. Biocompatibility results show higher phenotypic retention of iPSC-CMs due to microenvironments enriched with native proteins. On the contrary, the scaffolds without myocardial proteins exhibit higher dedifferentiation of iPSC-CMs, proving that ECM proteins provide a suitable microenvironment for iPSC-CMs. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=128 SRC="FIGDIR/small/673432v1_ufig1.gif" ALT="Figure 1"> View larger version (51K): org.highwire.dtl.DTLVardef@31a497org.highwire.dtl.DTLVardef@12cee05org.highwire.dtl.DTLVardef@beca77org.highwire.dtl.DTLVardef@1de5337_HPS_FORMAT_FIGEXP M_FIG C_FIG

bioengineering↗

bioRxiv2023

Development of Fully Human, Bispecific Antibodies that Effectively Block Omicron Variant Pseudovirus Infections

The emergence of highly immune invasive and transmissible variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has decreased the effectiveness of existing vaccines. It is, therefore, critical to develop effective and safe therapeutics for SARS-CoV-2 infections, especially for the most vulnerable and immunocompromised patients. Neutralizing antibodies have been shown to be successful at preventing severe disease from early SARS-CoV-2 strains, although their efficacy has diminished with the emergence of new variants. Here, we aim to develop fully human and broadly neutralizing monoclonal (mAb) and bispecific (BsAb) antibodies against SARS-CoV-2 and its variants. Specifically, we first identified two antibodies from human transgenic mice that bind to the receptor binding domain (RBD) of the SARS-CoV-2 spike protein and are capable of neutralizing SARS-CoV-2 and variants of concern with high to moderate affinity. Two non-competing clones with the highest affinity and functional blocking of ACE2 binding were then selected to be engineered into two BsAbs, which were then demonstrated to have relatively improved affinity, ACE2 blocking ability, and pseudovirus inhibition against several variants, including Omicron (B.1.1.529). Our findings provide one mAb candidate and two bsAb candidates for consideration of further clinical development and suggest that the bispecific format may be more effective than mAbs for SARS-CoV-2 treatment.

biochemistry↗

bioRxiv2019

Genome-wide analysis of chalcone synthase (CHS) family from eggplant (Solanum melongena L.) in flavonoid biosynthetic pathway and expression pattern in response to heat stress

Enzymes of chalcone synthase (CHS) family participate in the synthesis of a series of secondary metabolites in plants, fungi and bacteria. CHS showed significant correlation to the accumulation patterns of anthocyanin. The peel color mainly determined by the content of anthocyanin, is a majority economic trait for eggplant affected by heat stress. A total of 7 CHS(SmCHS1-7) putative genes were identified in genome-wide of eggplant (S. melongena L.). The SmCHS genes distribute on 7 scaffolds and were classified into 3 clusters. Phylogenetic relationships analysis showed that 73 CHS genes from 7 Solanaceae species were classified into 10 groups. SmCHS5, SmCHS6 and SmCHS7 were continuously down-regulated under 38{degrees}C and 45{degrees}C treatment, while SmCHS4 was up-regulated under 38{degrees}C but little change at 45{degrees}C in peel. Expression profiles of anthocyanin biosynthesis key genes families showed that the PAL, 4CL and AN11 genes were mainly expressed in all five tissues. CHI, F3H, F35H, DFR, 3GT and bHLH1 genes were expressed in flower and peel. Under heat stress, 52 key genes expression level were reduced under heat stress. By contrast, expression patterns of eight key genes similar to SmCHS4 up-regulated at the 38{degrees}C-3h. Comparative analysis of putative CHS protein biochemical characteristics, cis-regulatory elements, regulatory network revealed that SmCHS genes family have conservation gene structure and functional diversification. SmCHS showed two or more expression patterns and execute multiple functions to regulate anthocyanin content. Combined with regulatory networks, it is possible to further understand the regulation mechanism of peel color in eggplant.

genomics↗