Nanomedicine for drug delivery

I received my formal training in nanomedicine for drug delivery from university of Paris in collaboration with university of Patras (Greece), and University of Pavia and have worked extensively on preformulation & formulation strategy, classical & controlled release dosage forms and related regulatory aspects of biotech drugs & advanced therapy. Some of my notable projects include

1. Liposomal hydrogels for extended drug release

Focus of this research was to synthesise liposomes encapsulating various drugs (both hydrophillic and hydrophobic) using conventional and microfluidic methods and fully characterise them using physicochemical techniques. Thin film hydration (TFH) was the conventional method used and precision nanosystem was used as a microfluidic synthesis path for these liposomes. These particles were further characterised using Dynamic Light Scattering (DLS) and Size exclusion chromatography (SEC).

After complete characterization, various hydrogels were considered for loading of liposomes. Hydrogels are considered as efficient drug delivery systems owing to the advantages they offer in terms of biocompatibility, biodegradability and sustained drug release. Scanning Electron Microscopy (SEM) gave further insights into pore size of synthesised hydrogels to understand extended release of drugs loaded inside liposomes that were uniformly dispersed in hydrogels.

Results showed that the novel system was biocompatible and drug was completed released over the period of 23 days. These results are promising and have demonstrated the potential of liposomal gels as an excellent scaffolds in tissue engineering by encapsulating peptides or growth hormones for prolonged release of drug in matrix. 

2. Chitosan coated liposomes for drug delivery to posterior eye segment

Drug delivery to the posterior eye is limited by epithelial and mucosal barriers limiting the topical administration of drugs leading to invasive modes of repeated long-term painful administration of drugs. Several constructs of liposomes have been prepared to counter this challenge yet are often limited by size and surface charge resulting in poor encapsulation efficiency, low retention time, and poor permeability. In this research, chitosan coated liposomes (CCL) were prepared to address these challenges. Conventional liposomes encapsulating Triamcinolone Acetonide (TA) were compared with their chitosan coated counterpart for drug loading and release studies. Results showed that the formulated nanosystem showed a higher encapsulation efficiency and a highly positive surface charge, increased retention time and sustained release. To test the system, Choroidal neovascularization (CNV) rat models were generated. They were used to assess the efficiency of CCLs as nanocarriers in drug delivery.

High pressure liquid chromatography (HPLC) was used to analyse presence of drug retaining in the eye and significant amount of TA was found to be present after fifteen days of treatment with CCL.

The results showed successful penetration of the construct via corneal mucosal barrier and its accumulation in vitreous body. The analysis shows that this chitosan based liposomal construct can be employed as a potential topical delivery system for treating posterior segment diseases.