Intratumoral delivery of Paclitaxel in solid tumor from biodegradable hyaluronan nanoparticle formulations

Polymeric drug delivery systems for localized cancer chemotherapy

Cancer has become one of the most difficult health challenges of our time, accounting for millions of deaths yearly. Systemic chemotherapy is the most common therapeutic approach; however, considerable limitations exist including toxicities to healthy tissues and low achievable drug concentrations at tumor sites. More than 85% of human cancers are solid tumors, which can greatly benefit from localized delivery. This approach allows for high drug concentrations at the target site, lower systemic toxicity, and extended drug exposure which may be beneficial for cell cycle-specific drugs. Polymers have been widely considered in the development of localized delivery systems. This review focuses on both natural and synthetic biodegradable polymers that have been explored for localized chemotherapy, exploring their advantages, disadvantages, and clinical potential while citing examples of their use in pre-clinical development.

A ceramic-based anticancer drug delivery system to treat breast cancer

Drug delivery systems offer the advantage of sustained targeted release with minimal side effect. In the present study, the therapeutic efficacy of a porous silica-calcium phosphate nanocomposite (SCPC) as a new delivery system for 5-Fluorouracil (5-FU) was evaluated in vitro and in vivo. In vitro studies showed that two formulations; SCPC50/5-FU and SCPC75/5-FU hybrids were very cytotoxic for 4T1 mammary tumor cells. In contrast, control SCPCs without drug did not show any measurable toxic effect. Release kinetics studies showed that SCPC75/5-FU hybrid provided a burst release of 5-FU in the first 24 h followed by a sustained release of a therapeutic dose (30.7 microg/day) of the drug for up to 32 days. Moreover, subcutaneous implantation of SCPC75/5-FU hybrid disk in an immunocompetent murine model of breast cancer stopped 4T1 tumor growth. Blood analyses showed comparable concentrations of Ca, P and Si in animals implanted with or without SCPC75 disks. These results strongly suggest that SCPC/5-FU hybrids can provide an effective treatment for solid tumors with minimal side effects.

Localized doxorubicin chemotherapy with a biopolymeric nanocarrier improves survival and reduces toxicity in xenografts of human breast cancer

Patients with metastatic breast cancer have a five-year survival rate of 27% compared to 98% for localized cancer, and the presence of even a few cancer cells in lymph nodes, known as isolated tumor cells or nanometastases, significantly increases the risk of relapse in the absence of aggressive treatment. Therefore, diagnosis and treatment of lymphatic metastases in early breast cancer plays an important role in patient survival. Here, we demonstrate the first description of a delivery system for localized doxorubicin chemotherapy to the breast tissue. The hyaluronan-doxorubicin nanoconjugate exhibits a sustained release characteristic in vitro and in vivo in the breast tissues of rodents bearing human breast cancer xenografts. In addition, the conjugate reduces dose-limiting cardiac toxicity with minimal toxicity observed in normal tissues. Finally, the conjugate dramatically inhibits breast cancer progression in vivo, leading to an increased survival rate. Thus, localized chemotherapy to the breast lymphatics with a nanocarrier may represent an improved strategy for treatment of early stage breast cancers.