Executive Summary : | This project proposal presents novel way of rapid fabrication of micro-needles. The fabricated micro-needles can be used various medical applications for transdermal drug delivery. The concept of unconstraint depth photopolymerization used in the Bulk Lithography process developed at IIT Bombay will be used for the fabrication of micro-needles and micro-needle arrays. In Bulk Lithography (BL) process laser beam is focused at resin substrate interface with no constraint on beam travel inside the resin. The process involves physical phenomena such as diffraction of laser because of a) spatial and temporal variation (intensity dependent) in the refractive index of voxel continuously getting cured and b) diffusion of photoinitiator (PI) radicals near the voxel induced by concentration gradients in PI because of light absorption. Due to these physical phenomena various shape and sizes of the voxels resembling micro-needle are observed. In this project a machine will be designed and fabricated for producing typical sizes of microneedle arrays based on the BL process. The physical phenomena mentioned above will be explored to develop templates (pattern) for microneedles molding with the controlled shapes and sizes. Parameters such as laser intensity, exposure time, focus distance, etc. would be used to characterize the shape and sizes of needles. Based on the generalized characterization, the process plan will be evolved for fabrication of patterns of micro-needles. The developed microneedle templates from Bulk Lithography will be surrounded by uncured resin. This uncured residual resin needs to be removed before using these templates for further processes. Hence, a freeze-drying technique after displacing resin with suitable solvent will be implemented to remove the uncured resin. The templates further processed for preparation of master mold of PDMS. Finally, the production of the microneedle arrays will be made using biocompatible material in PDMS master mold. Unique needle geometries such as needle structures with undercuts at the base will be explored. Methods in current state-of-the-art cannot obtain such geometry which ensures the gripping of the fabricated patch with skin for enhanced drug delivery. Besides, pointed-tip microneedles with sufficient mechanical properties provide potential use as a painless drug delivery system to penetrate the skin without tip damage. Further, the obtained biocompatible microneedles will then be handed over to the Institute for Stem Cell Science and Regenerative Medicine (InStem, Bangalore), and the preclinical trials would be explored for drug delivery by InStem. Thus, the project will be completed at IIT Bombay and InStem (Bangalore) jointly. |
Co-PI: | Dr. Kiran Suresh Bhole, Sardar Patel College Of Engineering, Mumbai, Maharashtra-400058, Dr. Praveen Kumar Vemula, Institute For Stem Cell Science And Regenerative Medicine (Instem), Bengaluru, Karnataka-560065 |