The quest for a better fight: How can nanomaterials address the current therapeutic and diagnostic obstacles in the fight against COVID-19?

SARS-CoV-2 Neutralization by Cell Membrane-Coated Antifouling Nanoparticles

The global outbreak of the COVID-19 pandemic has indisputably wreaked havoc on societies worldwide, compelling the scientific community to seek urgently needed therapeutic agents with low-cost and low-side effect profiles. Numerous approaches have been investigated in the quest to prevent or treat COVID-19, but many of them exhibit unwelcome side effects, such as dysfunctional viral immune responses and inflammation. Herein, we present the preparation of solid natural human pulmonary alveolar epithelial cell (ATII) membrane-coated PLGA NPs (PLGA NPs@ATII-M), which demonstrate remarkable affinity and competitiveness to neutralize the SARS-CoV-2 S1 protein-coated NPs (SCMMA NPs-S1), which are employed as a surrogate for coronavirus particles. In addition, we first considered the antifouling properties of these types of NPs, and we found that this membrane-coated NP formulation boasts excellent antifouling capabilities, which serve to protect their neutralization properties out of shielding by protein coronas in blood circulation. Moreover, this formulation is easily prepared and stored with a low-cost profile and exhibits good specificity, high targeting efficiency, and potentially side effect avoiding, thus making it a highly promising candidate for COVID-19 treatment.

Advanced Nitric Oxide Generating Nanomedicine for Therapeutic Applications

Nitric oxide (NO), a gaseous transmitter extensively present in the human body, regulates vascular relaxation, immune response, inflammation, neurotransmission, and other crucial functions. Nitrite donors have been used clinically to treat angina, heart failure, pulmonary hypertension, and erectile dysfunction. Based on NO's vast biological functions, it further can treat tumors, bacteria/biofilms and other infections, wound healing, eye diseases, and osteoporosis. However, delivering NO is challenging due to uncontrolled blood circulation release and a half-life of under five seconds. With advanced biotechnology and the development of nanomedicine, NO donors packaged with multifunctional nanocarriers by physically embedding or chemically conjugating have been reported to show improved therapeutic efficacy and reduced side effects. Herein, we review and discuss recent applications of NO nanomedicines, their therapeutic mechanisms, and the challenges of NO nanomedicines for future scientific studies and clinical applications. As NO enables the inhibition of the replication of DNA and RNA in infectious microbes, including COVID-19 coronaviruses and malaria parasites, we highlight the potential of NO nanomedicines for antipandemic efforts. This review aims to provide deep insights and practical hints into design strategies and applications of NO nanomedicines.

Preparation and evaluation of the anti-cancer properties of RGD-modified curcumin-loaded chitosan/perfluorohexane nanocapsules in vitro

Curcumin (Cur) encapsulation in nanocapsules (NCs) could improve its availability and therapeutic antitumor efficacy. Cur-loaded chitosan/perfluorohexane (CS/PFH) nanocapsules (CS/PFH-Cur-NCs) were thus synthesized via a nanoemulsion process. To further enhance the selective tumor targeting ability of Cur-loaded NCs, a novel CS/PFH-Cur-NCs with conjugation of Arg-Gly-Asp (RGD) peptide (RGD-CS/PFH-Cur-NCs) were prepared in this study. The properties of these NCs were then explored through in vitro release experiments and confocal laser scanning microscopy-based analyses of the ability of these NCs to target MDA-MB-231 breast cancer cells. In addition, an MTT assay-based approach was used to compare the relative cytotoxic impact of CS/PFH-Cur-NCs and RGD-CS/PFH-Cur-NCs on these breast cancer cells. It was found that both CS/PFH-Cur-NCs and RGD-CS/PFH-Cur-NCs were smooth, relatively uniform, spheroid particles, with the latter being 531.20 ± 68.97 nm in size. These RGD-CS/PFH-Cur-NCs can be ideal for contrast imaging studies, and were better able to target breast cancer cells in comparison to CS/PFH-Cur-NCs. In addition, RGD-CS/PFH-Cur-NCs were observed to induce cytotoxic MDA-MB-231 cell death more swiftly in comparison to CS/PFH-Cur-NCs. These findings suggest that NC encapsulation and RGD surface modification can remarkably improve the anti-tumor efficacy of Cur. These novel NCs may thus manifest a significant potential value in the realm of image-guided cancer therapy, underscoring an important direction for future research.