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Paclitaxel gelatin nanoparticles for intravesical bladder cancer therapy
Ze Lu1, Teng-Kuang Yeh, Jie Wang
1Optimum Therapeutics, L.L.C., Columbus, Ohio, USA.
Purpose:
We have noted that inadequate drug delivery to tumor cells is a major cause of failed intravesical therapy for nonmuscle invading bladder cancer, partly due to the dilution of drug concentration by urine production during treatment. To address this problem we developed gelatin nanoparticles of paclitaxel designed to yield constant drug concentrations. The hypothesis that a constant, therapeutic concentration in urine, bladder tissue and tumors can be attained was evaluated in dogs.
Materials And Methods:
We studied drug release from paclitaxel gelatin nanoparticles in culture medium in vitro. In vivo studies were performed in tumor-free dogs and in pet dogs with naturally occurring transitional cell carcinoma, in which the pharmacokinetics of paclitaxel gelatin nanoparticles were determined in plasma, urine and tumors.
Results:
Paclitaxel release from paclitaxel gelatin nanoparticles in vitro and in vivo was rate limited by the drug solubility in aqueous medium. This property yielded constant drug concentrations independent of changes in urine volume during the 2-hour treatment. Intravesical paclitaxel gelatin nanoparticles showed low systemic absorption, and favorable bladder tissue/tumor targeting and retention properties with pharmacologically active concentrations retained in tumors for at least 1 week.
Conclusions:
Constant drug release from paclitaxel gelatin nanoparticles may overcome the problem of drug dilution by newly produced urine and the sustained drug levels in tumors may decrease treatment frequency.
Insights
Gelatin nanoparticles of paclitaxel provide constant drug concentrations for intravesical therapy in bladder cancer. This overcomes urine dilution and maintains therapeutic levels in tumors for extended periods.
Area of Science:
- Oncology
- Nanotechnology
- Pharmacology
Background:
- Intravesical therapy for nonmuscle invasive bladder cancer often fails due to inadequate drug delivery.
- Urine production during treatment dilutes drug concentration, reducing efficacy.
Purpose of the Study:
- To develop paclitaxel-loaded gelatin nanoparticles for sustained intravesical drug delivery.
- To evaluate if these nanoparticles maintain constant therapeutic drug concentrations in urine, bladder tissue, and tumors.
Main Methods:
- In vitro drug release studies of paclitaxel gelatin nanoparticles in culture medium.
- In vivo pharmacokinetic studies in tumor-free and tumor-bearing dogs, analyzing drug concentrations in plasma, urine, and tumors.
Main Results:
- Paclitaxel release was rate-limited by solubility, ensuring constant concentrations independent of urine volume.
- Nanoparticles demonstrated low systemic absorption with favorable targeting and retention in bladder tissue and tumors.
- Pharmacologically active drug concentrations were maintained in tumors for at least one week.
Conclusions:
- Constant drug release from paclitaxel gelatin nanoparticles addresses drug dilution by urine.
- Sustained drug levels in tumors offer potential for reduced treatment frequency in bladder cancer therapy.
