Polymeric Core-Shell Combinatorial Nanomedicine for Synergistic Anticancer Therapy

Immobilization of Olive Leaf Extract with Chitosan Nanoparticles as an Adjunct to Enhance Cytotoxicity

We immobilized the olive leaf extract (OLE) with chitosan nanoparticles (CNPs) by optimizing the effect of various immobilization conditions, and OLE-loaded CNPs (OLE-CNPs) were then elaborately characterized physicochemically by scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectroscopy, dynamic light scattering (DLS), and atomic force microscopy (AFM). Under optimal conditions, CNPs were able to accommodate the OLE with a loading capacity of 97.5%. The resulting OLE-CNPs had a spherical morphology, and their average diameter was approximately 100 nm. The cytotoxic influence, cell cycle distribution, and apoptosis stage of OLE and OLE-CNPs were analyzed on lung carcinoma (A549) and breast adenocarcinoma (MCF-7) cell lines. In an in vitro cytotoxic assay, IC50 values of OLE-CNPs were determined to be 540 μg/mL for A549 and 810 μg/mL for MCF-7. The treatment of both A549 and MCF-7 with OLE-CNPs caused the highest cell arrest in G0/G1 in a dose-independent manner. OLE-CNPs affected cell cycle distribution in a manner different from free OLE treatment in both cancer cells. A549 and MCF-7 cells were predominantly found in the late apoptosis and necrosis phases, respectively, upon treatment of 1000 μM OLE-CNPs. Our results suggest that CNPs enhance the utility of OLEs as nutraceuticals in cancer and that OLE-CNPs can be utilized as an adjunct to cancer therapy.

Chitosan and its derivatives as polymeric anti-viral therapeutics and potential anti-SARS-CoV-2 nanomedicine

The coronavirus pandemic, COVID-19 has a global impact on the lives and livelihoods of people. It is characterized by a widespread infection by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), where infected patients may develop serious medical complications or even face death. Development of therapeutic is essential to reduce the morbidity and mortality of infected patients. Chitosan is a versatile biomaterial in nanomedicine and exhibits anti-microbial, anti-cancer and immunomodulatory properties. This review highlights the progress in chitosan design and application pertaining to the anti-viral effects of chitosan and chitosan derivatives (hydroxypropyl trimethylammonium, sulfate, carboxymethyl, bromine, sialylglycopolymer, peptide and phosphonium conjugates) as a function of molecular weight, degree of deacetylation, type of substituents and their degree and site of substitution. The physicochemical attributes of these polymeric therapeutics are identified against the possibility of processing them into nanomedicine which can confer a higher level of anti-viral efficacy. The designs of chitosan for the purpose of targeting SARS-CoV-2, as well as the ever-evolving strains of viruses with a broad spectrum anti-viral activity to meet pandemic preparedness at the early stages of outbreak are discussed.

Application and Analysis of 6-Mercaptopurine Nanomedicine in the Treatment of Leukemia

As a first-line drug widely used in the treatment of leukemia, 6-MP has obvious effects on leukemia. However, 6-MP disadvantages such as poor solubility in water, easy binding with serum proteins, short circulation time, and large toxic and side effects greatly limit the application of 6-MP. For this reason, various 6-MP nano drug-loading systems have been designed to increase the water solubility of 6-MP, extend the circulation time, and increase the bioavailability of 6-MP to a certain extent, reducing its toxic and side effects. However, its therapeutic effect in vivo and in vitro is still far from expectations, and there is a lot of room for improvement. In order to solve the above problems encountered in the clinical application of 6-MP, we have tried two ways of polymer prodrugs and drug-loaded vesicles to achieve efficient targeted delivery and treatment of 6-MP. We designed hyaluronic acid (HA)-based gluteal-skin-responsive 6-MP polymer prodrug (HA-GS-MP) for highly effective targeted therapy of acute myeloid leukemia. Hyaluronic acid is a natural polysaccharide, which has excellent biocompatibility and biodegradability, and has a good ability to actively target malignant tumor cells overexpressing the CD₄₄ receptor. 6-MP is connected to the HA chain through a vinyl sulfide bond, which is stable under physiological conditions (no drug release), and under intracellular reducing conditions, the connection bond is broken and 6-MP is quickly released. HA-GS-MP has a simple preparation process, good water solubility, long cycle time, and strong targeting ability. This GSH-responsive CD₄₄ targeted 6-MP polymer prodrug is expected to improve the therapeutic effect on acute myeloid leukemia cells.

Glycol chitosan in situ coating on PLGA nanoparticle curtails extraneous paclitaxel precipitates and imparts protein corona independent hemocompatibility

Poly (lactide-co-glycolide) (PLGA) nanoparticles surface functionalized with water soluble glycol chitosan (GC) and carboxymethyl chitosan (CMC) has been studied for their drug (Paclitaxel and Doxorubicin) loading, yield, cellular uptake, serum protein adsorption and hemocompatibility. It was observed that Paclitaxel (Ptxl) phase out as Extraneous Ptxl Precipitates (EPP) (>25 %) in case of uncoated and CMC coated low molecular weight (LMW) PLGA nanoparticles (PNPs). The EPP formation was significantly reduced to ∼5 % with GC coating as it enhanced LMW PLGA precipitation and yield predominantly spherical polymeric nanoparticles towards better encapsulation of Ptxl and thus uniform intracellular drug distribution. Interestingly, protein corona analysis showed cmcPNPs and gcPNPs to be distinct from each other in associating mainly with serum proteins of molecular weight < 30 kDa and >30 kDa respectively. While CMC functionalization showed >10 % hemolysis, at similar concentration GC coating was found to provide superior hemocompatibility even in the absence of protein corona.