Functionalized bioadhesion-enhanced carboxymethyl cellulose/polyvinyl alcohol hybrid hydrogels for chronic wound dressing applications.

Wounds produced by trauma, burns, and chronic diseases cause millions of patients to suffer discomfort, pain, and, in many cases, disability and death, leading to enormous health, social and financial impacts globally. Regrettably, current clinical treatments for chronic wounds remain unsatisfactory. Thus, this study reports for the first time the design, development, and synthesis of chemically biofunctionalized hybrid hydrogels made of carboxymethyl cellulose (CMC) and poly(vinyl alcohol) (PVA) crosslinked by citric acid using an entirely biocompatible and green process. They demonstrated suitable physicochemical properties, cytocompatibility, and hemocompatibility to be applied as a smart wound dressing for skin tissue engineering. These novel hybrids were biofunctionalized with l-arginine and RGD peptide through carbodiimide mediated-amide formation to promote bioadhesion of fibroblast and keratinocyte cells as a potential enhancement for wound healing and skin tissue engineering applications.

Gold nanoparticle-carboxymethyl cellulose nanocolloids for detection of human immunodeficiency virus type-1 (HIV-1) using laser light scattering immunoassay.

It is estimated that over 100 million people have been infected with human immunodeficiency virus (HIV-1) resulting in approximately 30 million deaths globally. Herein, we designed and developed novel nano-immunoconjugates using gold nanoparticles (AuNPs) and carboxymethylcellulose (CMC) biopolymer, which performed simultaneously as an eco-friendly in situ reducing agent and surface stabilizing ligand for the aqueous colloidal process. These AuNPs-CMC nanocolloids were biofunctionalized with the gp41 glycoprotein receptor (AuNPs-CMC-gp41) or HIV monoclonal antibodies (AuNPs-CMC_PolyArg-abHIV) for detection using the laser light scattering immunoassay (LIA). These AuNPs-CMC bioengineered nanoconjugates were extensively characterized by morphological and physicochemical methods, which demonstrated the formation of spherical nanocrystalline colloidal AuNPs with the average size from 12 to 20 nm and surface plasmon resonance peak at 520 nm. Thus, stable nanocolloids were formed with core-shell nanostructures composed of AuNPs and biomacromolecules of CMC-gp41, which were cytocompatible based on in vitro cell viability results. The AuNPs-CMC-gp41 nanoconjugates were tested against HIV monoclonal antibodies conjugates (AuNPs-CMC_PolyArg-abHIV) using the light scattering immunoassay (LIA) where they behaved as active nanoprobes for the detection at nM level of HIV-1 antigenic proteins. This strategy offers a novel nanoplatform for creating bioprobes using green nanotechnology for the detection of HIV-1 and other virus-related diseases.

In vitro and in vivo assessment of nanotoxicity of CdS quantum dot/aminopolysaccharide bionanoconjugates.

The nanotoxicity of Cd-containing quantum dots (QDs) for biomedical applications is very controversial and not completely understood. In this study, we evaluated the cytotoxicity of surface-biofunctionalized CdS QDs with chitosan directly synthesized via aqueous route at room temperature. These core-shell CdS-chitosan nanoconjugates showed different degrees of cytotoxic responses using MTT cell proliferation assay toward three human cell cultures, human osteosarcoma cell line (SAOS), non-Hodgkin's B cell lymphoma (Toledo), and human embryonic kidney cell line (HEK293T), under three exposure times (1, 3, and 5days) and three colloidal concentrations (10nM, 50nM, and 100nM). The results clearly demonstrated that the CdS QDs, regardless to the fact that they were coated with a biocompatible aminopolysaccharide shell, induced a severe dose- and time-dependent inhibition of cell viability. In addition, the HEK293T and SAOS cell lines showed much more sensitive response compared to Toledo, which indicated that the cytotoxicity was also cell-type dependent. The exceptional resistance of Toledo cells to toxic effects of CdS nanoconjugates even at severe test conditions was assigned to specific role of B-lineage cells of the immune defense system. Remarkably, no conclusive evidence of toxicity of CdS nanoconjugates was observed in vivo using intravenous injections of CdS nanoconjugates in BALB/c mouse animal models for 30days, but localized fluorescence was detected in ex-vivo liver tissue samples. Therefore, these results prove that there is no guarantee of "risk-free" use of CdS nanoconjugates for in vivo applications, even when functionalized with biopolymer ligands, as they can pose an excessive threat due to unpredicted and uncorrelated responses under in vitro and in vivo biological assays with highly toxic cadmium ions.