The development of drug delivery systems with microencapsulated therapeutic agents is a promising approach to the sustained and controlled delivery of various drug molecules. The incorporation of dual release kinetics to such delivery devices further adds to their applicability. Herein, novel core-shell scaffolds composed of sodium deoxycholate and trishydroxymethylaminomethane (NaDC-Tris) have been developed with the aim of delivering two different drugs with variable release rates using the same delivery vehicle. Data obtained from XRD studies, sol-gel transition temperature measurement, rheology and fluorescence studies of the core-shell systems indicate a significant alteration in the core and the shell microstructural properties in a given system as compared to the pure hydrogels of identical compositions. The release of the model drugs Fluorescein (FL) and Rhodamine B (RhB) from the shell and the core, respectively, of the two core-shell designs studied exhibited distinctly different release kinetics. In the 25@250 core-shell system, 100% release of FL from the shell and 19% release of RhB from the core was observed within the first 5 hours, while 24.5 hours was required for the complete release of RhB from the core. For the 100@250 system, similar behaviour was observed with varied release rates and a sigmoidal increase in the core release rate upon disappearance from the shell. Cell viability studies suggested the minimal toxicity of the developed delivery vehicles towards NMuMG and WI-38 cells in the concentration range investigated. The reported core-shell systems composed of a single low molecular weight gelator with dual release kinetics may be designed as per the desired application for the consecutive release of therapeutic agents as required, as well as combination therapy commonly used to treat diseases such as diabetes and cancer.

No abstract

Low Molecular Weight (LMW) amphiphiles are promising class of chemicals that often enable gelation through formation of supramolecular self-assemblies driven by physical forces such as hydrophobic, hydrogen bonding and π-π interactions. These gels are of prime importance for wide range of biomedical applications like 3D-cell culture, enzyme immobilization, drug delivery, self-healing bandages etc. due to their ease of fabrication, biocompatibility, biodegradability, ease of modification and reversibility. However, low mechanical strength limit the applications of these physical gels. Herein, various strategies that have been adopted over the past two decades to advance the properties of different LMW gels are summarized. Structural modification in urea, saccharides, amino acids, peptides, bile acids and nucleobases induce functionalities in the corresponding gels that demonstrate applications such as injectable drug delivery vehicles, stimuli responsive delivery agent, pollutant adsorbents, catalysts, antimicrobial activity to name a few. The review also emphasizes on the developments in the field of engineered gels such as core-shell, double network and nanocomposite gel scaffolds that emphasizes on a facile modification of LMW gels to yield soft materials with higher toughness and tensile strength to be utilized for biomedical applications. The review also points toward the arenas which lack sufficient investigation and wherein the scope for further development remains.

No abstract

No abstract