Interfacial behavior of PEGylated lipids and their effect on the stability of squalenoyl-drug nanoassemblies

Novel Nanotherapeutic Systems Based on PEGylated Squalene Micelles for Enhanced In Vitro Activity of Methotrexate and Cytarabine

Nanomedicine has garnered significant attention due to the advantages it offers in the treatment of cancer-related disorders, some of the deadliest diseases affecting human lives. Conventional medication formulations often encounter issues of instability or insolubility in biological environments, resulting in low bioavailability. Nanocarriers play a crucial role in transporting and safeguarding drugs at specific sites of action, enabling gradual release under particular conditions. This study focuses on methotrexate (MTx) and cytarabine (Cyt), essential antitumoral drugs, loaded into PEGylated squalene micellar structures to enhance therapeutic effectiveness and minimize drawbacks. The micelles were prepared using ultrasound-assisted methods in both water and phosphate buffer saline solutions. Evaluation of drug-loaded micelles encompassed parameters such as particle size, colloidal stability, surface charge, morphology, encapsulation efficiency, drug loading capacity, and in vitro release profiles under simulated physiological and tumoral conditions. In vitro cell inhibition studies conducted on MCF-7 and HeLa cell lines demonstrated higher antitumoral activity for the drug-encapsulated micelles compared to free drugs. The encapsulation effectively addressed the burst effect, providing sustained release for at least 48 h while enhancing the drug's protection under physiological conditions.

Baicalein Loaded Crown Ether-mPEG-PLGA Micelle Drug Delivery System for Increased Breast Cancer Treatment: Preparation, Characterization, In-Vitro and In-Vivo Evaluations

Due to low aqueous solubility and poor bioavailability of the flavone baicalein (BIC), a nano-micelle of delivery system was developed. Preparation of BIC-loaded crown ether-mPEG-PLGA micelle (BCPP-M) was performed via thin-film hydration method. Characterization of micellar excipients was accomplished with 1H NMR, while evaluation of the optimal BCPP-M formulation was appropriately carried out through zeta potential (ZP), size of particles (PS), efficiency of encapsulation (EE) and capacity of drug loading (DL). We evaluated BIC release In-Vitro and profile of In-Vivo pharmacokinetics. Evaluation of the anti-breast cancer property of BCPP-M using MCP-7 cells cytotoxicity and mice model was performed. Particles of BCPP-M were homogenously and spherically shaped with smaller average PS, coupled with higher EE and DL, good stability and polydispersity index (PDI). The accumulative release of BCPP-M was obviously higher than free-BIC. Significantly, oral biological availability of BCPP-M was improved comparable to free BIC. Besides, half maximum inhibitory concentration (IC50) of BCPP-M in MCP-7 cells was lower than free-BIC. Animal experiments also showed targeting, long circulation and antitumor potential of BCPP-M. Successful incorporation of BIC into long-acting and targeting micellar system could have enhanced solubility in aqueous media, oral In-Vivo availability and antitumor property of BIC.

Synthesis of a biodegradable branched copolymer mPEG-b-PLGA-g-OCol and its pH-sensitive micelle

An amphiphilic biodegradable branched copolymer, mPEG-b-PLGA-g-OCol, was synthesized by grafting copolymer (methoxy polyethylene glycol)-b-Poly (l,d-lactic-co-glycolic acid) (mPEG-b-PLGA) on oligomeric collagen (OCol), to form a branched structure with mPEG-b-PLGA as side chain and OCol as backbone. mPEG-b-PLGA and mPEG-b-PLGA-g-OCol were both amphipathic and can self-assemble into micelles in aqueous solution. The mPEG-b-PLGA-g-OCol micelles showed pH-sensitive behaviors and the particle size below 100 nm in slightly acidic environment such as tumor tissue milieu interieur to perform passive targeting. Observed by SEM, when the solution pH increased from 5 to 9, the morphology of mPEG-b-PLGA-g-OCol micelles changed from small spheres to larger ones to rings. For biodegradable mPEG-b-PLGA-g-OCol, the micelles will gradually degrade in body. Further, doxorubicin (DOX) was effectively loaded in the micelles with drug loading and encapsulation efficiency of 3.48% and 25.8%, respectively. To evaluate antineoplastic effect of DOX-laden micelles in vitro, MTT test, flow cytometry and CLSM were performed and found that DOX-laden micelles exhibited higher cellular proliferation inhibition against HeLa cells. These features indicated that the mPEG-b-PLGA-g-OCol micelles were potential drug carrier for cancer therapy.

Novel delivery approaches for cancer therapeutics

Currently, a majority of cancer treatment strategies are based on the removal of tumor mass mainly by surgery. Chemical and physical treatments such as chemo- and radiotherapies have also made a major contribution in inhibiting rapid growth of malignant cells. Furthermore, these approaches are often combined to enhance therapeutic indices. It is widely known that surgery, chemo- and radiotherapy also inhibit normal cells growth. In addition, these treatment modalities are associated with severe side effects and high toxicity which in turn lead to low quality of life. This review encompasses novel strategies for more effective chemotherapeutic delivery aiming to generate better prognosis. Currently, cancer treatment is a highly dynamic field and significant advances are being made in the development of novel cancer treatment strategies. In contrast to conventional cancer therapeutics, novel approaches such as ligand or receptor based targeting, triggered release, intracellular drug targeting, gene delivery, cancer stem cell therapy, magnetic drug targeting and ultrasound-mediated drug delivery, have added new modalities for cancer treatment. These approaches have led to selective detection of malignant cells leading to their eradication with minimal side effects. Lowering multi-drug resistance and involving influx transportation in targeted drug delivery to cancer cells can also contribute significantly in the therapeutic interventions in cancer.