Structural studies on aqueous gelatin solutions: Implications in designing a thermo-responsive nanoparticulate formulation.
Gelatin as a polymer has found extensive application in the pharmaceutical industry. It is also being used, as a matrix molecule, for nanoparticle based drug delivery applications. Gelatin nanoparticles synthesised, keeping the native structure intact, show interesting properties. Synthesizing such nanoparticles requires an understanding of the structural features of gelatin under conditions of nanoparticle synthesis and preserving them during the process. To address this we have carried out an extensive characterization of gelatin using circular dichroism (CD) spectroscopy, differential scanning calorimetry (DSC) and scanning electron microscopy (SEM) under various reaction conditions that are utilized in the desolvation method for gelatin nanoparticle synthesis. We investigated the gel-sol transition, hysteresis and gelatin fibre morphology under different pH and temperature conditions. We also investigated the temperature and pH dependence of triple-helix to random-coil transition in gelatin. We finally demonstrate the synthesis of gelatin nanoparticles with native gelatin. These nanoparticles show shrinkage in size (∼90nm) with increase in temperature from 30°C (369.4 ±19.8) to 40°C (282.3±9.8). Our results suggest that by carefully selecting the reaction conditions, it is possible to synthesise nanoparticles having partially folded structures and with a varying degree of sensitivity towards temperature and pH.
Centre for Cellular and Molecular Biology (CCMB), Uppal Road, Hyderabad 500 007, Telangana, India.
Saad M
SM
Ahsan
Centre for Cellular and Molecular Biology (CCMB), Uppal Road, Hyderabad 500 007, Telangana, India. Electronic address: mohan@ccmb.res.in.
Ch Mohan
CM
Rao
D004337:Drug Carriers / Q000737:chemistry*; D005780:Gelatin / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D010316:Particle Size; D044367:Phase Transition; D017510:Protein Folding; D017433:Protein Structure, Secondary; D012995:Solubility; D013696:Temperature
D004337:Drug Carriers; D005780:Gelatin
Gel-sol transition; Thermo-responsive gelatin nanoparticles; Triple helix-random coil transition