Author ORCID Identifier
Document Type
Thesis
Date of Award
2025
Degree Name
Master of Science (MS)
Department
Chemistry
First Advisor
Grigoriy A. Sereda
Abstract
Dental diseases are mostly caused by bacterial infections in the teeth, forming biofilms that release acids and decay the enamel of the teeth. More than half of the world's population were affected by oral diseases, including periodontitis (gum disease), dental caries (cavities), and oral cancer. Chlorhexidine (CHX) is the mostly used antimicrobial drug for dental diseases, but its overexposure to the healthy teeth causes many side effects, such as tooth staining, taste alteration, and many more. Taking advantage of the acidic environment of infected teeth, we designed a pH responsive targeted drug delivery system using calcium carbonate microparticles (CCMPs) as a drug carrier, coated with different sources of casein—pure analytical grade casein, skimmed milk, and diluted skimmed milk. Casein acts as a gatekeeping element, holding the drug at a normal pH of 7.4 and releasing CHX more at a low pH of 5.5, when the particle core degrades. Here, the drug release profiles of two different forms of CHX (base and salt form) were evaluated at pH 7.4 and pH 5.5. The characterizations of the particles were done using SEM, FT-IR, XRD spectroscopy, and zeta potential. For the porosity of the particles, BET N2 absorption/desorption surface analyzer was used. The adhesion of casein coated CCMPs shows the importance of drug adhered on the surface of the teeth for the initial treatment of bacterial infected teeth and occlusion of dentin opening tubules as a cure of hypersensitivity. Further, the antibacterial activity of our particles was examined against Streptococcus mutans (the most common bacteria causing dental decay) through the standard plate count method. Our results showed that skimmed milk and diluted skimmed milk hold the drug inside particles better than analytical grade casein at pH 7.4. In addition, CHX loaded particles coated with skimmed milk exhibited greater antibacterial activity at pH 5.5 than at pH 7.4. For future work, we are designing and fabricating a tooth-on-a-chip microfluidics device to evaluate the penetration efficacy of the released drug through the dentinal tubules, and for modeling of Streptococcus mutans – affected tooth inside the device.
Subject Categories
Chemistry | Dentistry
Keywords
Acid responsive Anti-bacterial Activity Calcium carbonate microparticles Casein and skimmed milk coating Chlorhexidine Targeted dental drug delivery
Number of Pages
86
Publisher
Uiversity of South Dakota
Recommended Citation
Joshi, Hem Raj, "CALCIUM CARBONATE MICROPARTICLES AS ACID RESPONSIVE TARGETED DRUG DELIVERY CARRIERS FOR ORAL DISEASES AND ITS ANTI-BACTERIAL ACTIVITY" (2025). Dissertations and Theses. 367.
https://red.library.usd.edu/diss-thesis/367