Micro-Raman Spectroscopy for Detection of Label-Free and Oil Red O Labeled PEGylated Nanoliposomes in hCmec/D3 Cell Internalization Studies

Rapid development of nanomedicines necessitates advancement in internalization techniques which can accurately distinguish between the complex environments of cells and nanocarriers. Internalization (or endocytosis) studies of oil red O labeled and label-free PEGylated-lecithin/cholesterol nanoliposomes was performed using micro-Raman spectroscopy. The C.O stretching vibrations and CCH scissoring bendings of naphthalene ring around 1225 cm.1 as well as the N=N stretching vibrations at 1377 cm.1 are prominent peaks absent from the label-free spectra which can be used for detection of internalized oil red O labeled nanoliposomes. Suitability of oil red O as a liposome marker was confirmed by stability studies of the incorporated dye and automated fluorescence cell counting. The C.C stretching region with a prominent wide band centered at 1080 cm.1 indicative of larger gauche conformer content typical for the lecithin-cholesterol nanoliposomes and the strong maximum at 980 cm.1 associated with O.C.C.N+ stretching vibrations of the liposome polar head groups are important for studying label-free nanoliposome cell internalization

Nanotechnology in medicine – our experiences

The success of design criteria for long-circulating drug delivery systems to support membrane receptor-ligand interaction and internalization has been limited and there is a need to develop smarter approaches for efficient drug tumor targeting. In order to overcome some of the current limitations, stimulus-responsive targeting has been combined with passive and active targeting strategies. More innovative nanocarriers that hold promise to optimize targeted drug delivery are systems with the ability for transformation from the stealth long-circulating form to cell interactive form in the complex tumor environment, exposing ligands at their surface for improved ligandreceptor interaction and cell internalization. This short review will be an overview of several nanomedicines designed and characterized by our research group, and the interplay between their physicochemical characteristics and biological fate

Nanotechnology – a robust tool for fighting the challenges of drug resistance in non-small cell lung cancer

Genomic and proteomic mutation analysis is the standard of care for selecting candidates for therapies with tyrosine kinase inhibitors against the human epidermal growth factor receptor (EGFR TKI therapies) and further monitoring cancer treatment efficacy and cancer development. Acquired resistance due to various genetic aberrations is an unavoidable problem during EGFR TKI therapy, leading to the rapid exhaustion of standard molecularly targeted therapeutic options against mutant variants. Attacking multiple molecular targets within one or several signaling pathways by co-delivery of multiple agents is a viable strategy for overcoming and preventing resistance to EGFR TKIs. However, because of the difference in pharmacokinetics among agents, combined therapies may not effectively reach their targets. The obstacles regarding the simultaneous co-delivery of therapeutic agents at the site of action can be overcome using nanomedicine as a platform and nanotools as delivery agents. Precision oncology research to identify targetable biomarkers and optimize tumor homing agents, hand in hand with designing multifunctional and multistage nanocarriers that respond to the inherent heterogeneity of the tumors, may resolve the challenges of inadequate tumor localization, improve intracellular internalization, and bring advantages over conventional nanocarrier

Design of ophthalmic micelles loaded with diclofenac sodium: effect of chitosan and temperature on the block-copolymer micellization behaviour

Diclofenac sodium 0.1% is a commonly used NSAID with well-documented clinical efficacy in reducing postoperative inflammation; however, its corneal tolerability and ophthalmic tissue bioavailability require further improvement. Advanced micellar delivery systems composed of block-copolymers and chitosan showing fine balance between the mucoadhesion and mucus permeation, capable to slip through the mucus barrier and adhere to the epithelial ocular surface, may be used to tackle both challenges. The aggregation behaviour of the block-copolymers in the presence of different additives will dramatically influence the quality attributes like particle size, particle size distribution, drug-polymer interaction, zeta potential, drug incorporation, important for the delicate balance among mucoadhesion and permeation, as well as safety and efficacy of the ophthalmic micelles. Therefore, quality by design approach and D-optimal experimental design model were used to create a pool of useful data for the influence of chitosan and the formulation factors on the block copolymer’s aggregation behaviour during the development and optimization of Diclofenac loaded Chitosan/Lutrol F127 or F68 micelles. Particle size, polydispersity index, dissolution rate, FTIR and DSC studies, NMR spectroscopy, cytotoxicity, mucoadhesivity, mucus permeation studies, and bioadhesivity were assessed as critical quality attributes. FTIR and DSC studies pointed to the chaotropic effect of chitosan during the micelle aggregation. Mainly, Pluronic F68 micellization behaviour was more dramatically affected by the presence of chitosan, and self-aggregation into larger micelles with high polydispersity index was favoured at higher chitosan concentration. The optimized formulation with highest potential for ophthalmic delivery of diclofenac sodium, good cytotoxicity profile, delicate balance of the mucoadhesivity, and mucus permeation was in the design space of Chitosan/Lutrol F127 micelles. Graphical abstract: [Figure not available: see fulltext.]The authors received financial support from the project Drug delivery systems for improved ophthalmic delivery, QUST-1-CPH2020-8, Qatar University