In Vitro Studies of Prednisolone Loaded PLGA Nanoparticles-Surface Functionalized With Folic Acid on Glioma and Macrophage Cell Lines

Polyesters and Polyester Nano- and Microcarriers for Drug Delivery

Many therapies require the transport of therapeutic compounds or substances encapsulated in carriers that reduce or, if possible, eliminate their direct contact with healthy tissue and components of the immune system, which may react to them as something foreign and dangerous to the patient's body. To date, inorganic nanoparticles, solid lipids, micelles and micellar aggregates, liposomes, polymeric micelles, and other polymer assemblies were tested as drug carriers. Specifically, using polymers creates a variety of options to prepare nanocarriers tailored to the chosen needs. Among polymers, aliphatic polyesters are a particularly important group. The review discusses controlled synthesis of poly(β-butyrolactone)s, polylactides, polyglycolide, poly(ε-caprolactone), and copolymers containing polymacrolactone units with double bonds suitable for preparation of functionalized nanoparticles. Discussed are syntheses of aliphatic polymers with controlled molar masses ranging from a few thousand to 106 and, in the case of polyesters with chiral centers in the chains, with controlled microstructure. The review presents also a collection of methods useful for the preparation of the drug-loaded nanocarriers: classical, developed and mastered more recently (e.g., nanoprecipitation), and forgotten but still with great potential (by the direct synthesis of the drug-loaded nanoparticles in the process comprising monomer and drug). The article describes also in-vitro and model in-vivo studies for the brain-targeted drugs based on polyester-containing nanocarriers and presents a brief update on the clinical studies and the polyester nanocarrier formulation approved for application in the clinics in South Korea for the treatment of breast, lung, and ovarian cancers.

Cancer nanomedicine: emergence, expansion, and expectations

The introduction of cancer nanomedicine has substantially enhanced the effectiveness of cancer treatments. Nano-formulations are becoming more prevalent among other treatment methods due to their improved therapeutic efficacy and low systemic toxicity. The discovery of the enhanced permeability and retention (EPR) effect has led to the development of numerous nanodrugs that passively target tumours. Then researchers identified certain cancer cells overexpress certain receptors, targeting these over-expressing receptors using targeting moiety on the surface of the nanoparticles becomes promising and surface functionalization of nanoparticles has become an important area of cancer nanomedicine. This leads to the physiochemical modification of nanoparticles for strengthening the EPR effect and active targeting. This review comprehensively outlines the origins of cancer nanomedicine, the role of the EPR effect, the tools of nanotechnology and their specifications, and the nature of passive and active targeting, which gives important direction for the progress of cancer therapy using nanomedicine. The review briefly enlists the available nano formulations for different cancers and attempts were made to account for the barriers to clinical translation. The review also briefly describes the transition of research from nanomedicine to nano-immunotherapy.

Effect of folate-targeted Erlotinib loaded human serum albumin nanoparticles on tumor size and survival rate in a rat model of glioblastoma

The aim of this study was to prepare folate-targeted Erlotinib loaded human serum albumin nanoparticles (FA-ERL-HSA NPs) and investigate in vitro cytotoxic and apoptotic effects using cell lines (U87MG and C6 cells) and an in vivo rat bearing C6 glioma model. The mean size of the FA-ERL-HSA NPs prepared using a desolvation method was 135 nm. In vitro MTT assays demonstrated that FA-ERL-HSA NPs had an IC₅₀ value of 52.18 μg/mL and 17.53 μg/mL compared to free ERL which had an IC₅₀ value of 119.8 μg/mL and 103.2 μg/mL for U87MG and C6 cells for 72 h, respectively. Flow cytometry results showed the apoptosis rate with FA-ERL-HSA NPs (100 μg/mL, 72 h) was higher compared to free ERL for both U87MG and C6 cells. Experiments using a rat glioblastoma model via TUNEL assay indicated that the apoptosis index of FA-ERL-HSA NPs was 48 % compared to 21 % for free ERL and the tumor size effectively decreased after a daily injection of 220 μg (2.5 mg/kg) from 87.45 mm³ (19th day) to 1.28 mm³ (60th day). The median survival rate of the rats increased after treatment to >100 days which was greater than controls.