Formulation and Evaluation of Aspirin-PLGA Microsphere for the Dental Stem Cell Stimulation

Aim: According to WHO, dental caries is the most prevalent oral disease, and its progression leads to tooth loss. Clinical management of caries focuses on the severity and extent of disease with the main aim, i.e., the ‘art’ of creating a good restoration. Recently, it has been reported that aspirin can stimulate existing stem cells and regenerate damaged teeth. But, the therapeutic effectiveness of a drug depends on developing a suitable novel drug delivery system, to retain at the site and suitably release the drug to produce effective therapy. Therefore, the present investigation intends to develop Aspirin-Poly lactic-co-glycolic acid microspheres for the restoration of dentin. Materials and Methods: Aspirin- Poly lactic-co-glycolic acid microsphere was formulated by the double emulsion technique and evaluated for particle size, encapsulation efficiency, characterization (differential scanning calorimetry, X-ray powder diffraction), in vitro release, as well as irritation testing using the Hen’s egg test-chorioallantoic membrane method. Results: The formulation exhibited good encapsulation efficiency (87.31±1.52%) and a particle size of 7.52 μm by Scaning Electron Micrscopy. In vitro release study exhibited sustained release (98.76±0.49%) for 16 days and triphasic release. This confirms that release is due to polymer erosion, swelling, and degradation. The ex vivo permeation study also confirmed sustained permeation and showed the significant partition and accumulation of the drug in the tissue. Further, the prepared formulation showed significantly low irritation compared to positive control by Hen’s Egg Test-Chorioallantoic Membrane method. Conclusion: Thus, the above finding suggests that the formulation can stimulate stem cells for the regeneration of dental tissue.