Conventional vs PEGylated loaded liposomal formulations by microfluidics for delivering hydrophilic chemotherapy

Developing drug delivery systems (DDSs) is one of the approaches used to improve cancer treatment, with the main goal of loading cancer drugs into a carrier targeting a specific organ and avoiding the distribution to healthy tissues. Nanoparticles (NPs) have been shown to be one of the optimum carriers that can be used as DDSs. Lipid-based NPs, such as liposomes, have been investigated in the current study due to their low toxicity and ability to carry hydrophilic and hydrophobic molecules. In the current studies, conventional liposomes composed of DPPC, and cholesterol and PEGylated liposomes composed of DPPC, cholesterol, and DSPE-PEG2000 are manufactured and loaded with Carboplatin. The study focused on investigating and comparing the impact of modifying the carboplatin-loaded liposomes with different concentrations of DSPE-PEG2000 on the NP diameter, polydispersity, ζ-potential, encapsulation efficiency (EE%), and drug release. The hydrodynamic microfluidic system was used to investigate any possible improvement in the EE% over other conventional methods. The results showed the microfluidic system's promising effect in enhancing the EE% of the Carboplatin. Moreover, the results showed a smaller diameter and higher stability of the PEGylated liposome. However, conventional liposomes represent better homogeneity and higher encapsulation efficiency for hydrophilic molecules.

Synthesis and Characterization of Paclitaxel-Loaded PEGylated Liposomes by the Microfluidics Method

For cancer therapy, paclitaxel (PX) possesses several limitations, including limited solubility and untargeted effects. Loading PX into nanoliposomes to enhance PX solubility and target their delivery as a drug delivery system has the potential to overcome these limitations. Over the other conventional method to prepare liposomes, a microfluidic system is used to formulate PX-loaded PEGylated liposomes. The impact of changing the flow rate ratio (FRR) between the aqueous and lipid phases on the particle size and polydispersity index (PDI) is investigated. Moreover, the effect of changing the polyethylene glycol (PEG) lipid ratio on the particle size, PDI, stability, encapsulation efficiency % (EE %), and release profile is studied. The physicochemical characteristics of the obtained formulation were analyzed by dynamic light scattering, FTIR spectroscopy, and AFM. This work aims to use microfluidic technology to produce PEGylated PX-loaded liposomes with a diameter of <200 nm, low PDI < 0.25 high homogeneity, and viable 28 day stability. The results show a significant impact of FRR and PEG lipid ratio on the empty liposomes' physicochemical characteristics. Among the prepared formulations, two formulations produce size-controlled, low PDI, and stable liposomes, which make them preferable for PX encapsulation. The average EE % was >90% for both formulations, and the variation in the PEG lipid ratio affected the EE % slightly; a high packing for PX was reported at different drug concentrations. A variation in the release profiles was notified for the different PEG lipid ratios.