Preparation of DOX-TPP/HA-ss-OA Nanoparticles, Investigation of Drug Release Behavior In Vitro, and Evaluation of Anti-proliferative Activity In Vitro.

Objective: This study aimed to develop and characterize DOX-TPP/HA-ss-OA nanoparticles, utilizing the mitochondria-targeting prodrug doxorubicin-triphenylphosphine (DOXTPP) and a reduction-sensitive amphiphilic polymer, hyaluronic acid-disulfide-oleic acid (HAss- OA). The research focused on evaluating the drug release behavior of these nanoparticles under varying glutathione (GSH) concentrations and their anti-tumor activity in vitro.

Methods: DOX-TPP/HA-ss-OA nanoparticles were prepared using probe ultrasound technology. The study examined the impact of different organic solvents on drug loading capacity and encapsulation efficiency to determine the optimal conditions. A single-factor experimental design was used to optimize the formulation process. Key parameters, including particle size and zeta potential, were measured to assess nanoparticle stability and performance. The dynamic dialysis method was employed to evaluate the reduction-sensitive drug release characteristics in media with different GSH concentrations. The MTT assay was used to analyze the growth-inhibitory effects of the nanoparticles on human breast cancer cells (MCF-7) and drug-resistant cells (MCF-7/ADR).

Results: The optimized preparation process for DOX-TPP/HA-ss-OA nanoparticles included a drug dosage of 2.0 mg, an oil-to-water volume ratio of 1:5, ultrasonic power of 500 W, and ultrasonic time of 15 minutes. The nanoparticles had an average particle size of 203.72 ± 2.30 nm and a zeta potential of 25.82 ± 0.58 mV, indicating favorable stability and effective drug delivery properties. The nanoparticles exhibited a slow, sustained release of DOX-TPP in pH 7.4 phosphate buffer solution (PBS) and accelerated release in high GSH concentrations, demonstrating reduction-responsive drug release. In vitro studies showed that DOX-TPP/HA-ss-OA nanoparticles significantly inhibited the proliferation of MCF-7 and MCF-7/ADR cells in a dosedependent manner, with enhanced efficacy compared to free DOX and other formulations.

Conclusion: DOX-TPP/HA-ss-OA nanoparticles demonstrate excellent reduction sensitivity, effective tumor cell growth inhibition in vitro, and the ability to overcome drug resistance. Including particle size and zeta potential measurements supports their suitability as drug carriers, highlighting their potential for targeted cancer therapy and further development.