orabase and Bone-Neoplasms

Effective treatment of metastatic castration resistant prostate cancer (mCRPC) remains an unmet challenge. Cabazitaxel (CBZ) is approved for mCRPC after docetaxel (DTX) failure, but the improvement in survival is only moderate (∼2 months) and patients suffer from significant side effects. Here, we report the development of a polymer based delivery system for CBZ to improve its safety and efficacy against DTX-resistant mCRPC. CBZ was conjugated to a carboxymethylcellulose-based polymer (Cellax-CBZ), which self-assembled into ∼100 nm particles in saline and exhibited sustained drug release in serum at 10%/day. Cellax-CBZ delivered 157-fold higher CBZ to PC3-RES prostate tumor in mice and could be safely administered at a 25-fold higher dose compared to free CBZ, resulting in superior tumor inhibition in multiple mice models of DTX-resistant CRPC. In a metastatic bone model of CRPC, Cellax-CBZ significantly improves overall survival with a 70% long-term survival rate to day 120, while mice treated with free CBZ had a median survival of 40 days. Cellax-CBZ induced mild and reversible neutropenia in mice but no other tissue damage. Cellax-CBZ showed significant potential for improving therapy of mCRPC over clinically approved CBZ.

Topics: Animals; Antineoplastic Agents; Bone Neoplasms; Carboxymethylcellulose Sodium; Cell Line, Tumor; Delayed-Action Preparations; Docetaxel; Drug Carriers; Drug Compounding; Drug Liberation; Drug Resistance, Neoplasm; Humans; Male; Maximum Tolerated Dose; Mice, Inbred NOD; Mice, SCID; Nanoparticles; Neutropenia; Particle Size; Prostatic Neoplasms, Castration-Resistant; Solubility; Taxoids; Tissue Distribution; Xenograft Model Antitumor Assays

A bioactive glass series (0.42SiO2-0.10Na2O-0.08CaO-(0.40-X)ZnO-(X)Ga2O3) was incorporated into carboxymethyl cellulose (CMC)/dextran (Dex) hydrogels in three different amounts (0.05, 0.10, and 0.25m(2)), and the resulting composites were characterized using transmission electron microscopy (TEM), differential scanning calorimetry (DSC), and (13)C Cross Polarization Magic Angle Spinning Nuclear Magnetic Resonance (CP MAS-NMR). Composite extracts were also evaluated in vitro against MG-63 osteosarcoma cells. TEM confirmed glass distribution throughout the composites, although some particle agglomeration was observed. DSC revealed that glass composition and content did have small effects on both Tg and Tm. MAS-NMR revealed that both CMC and Dex were successfully functionalized, that cross-linking occurred, and that glass addition did slightly alter bonding environments. Cell viability analysis suggested that extracts of the glass and composites with the largest Ga-content significantly decreased MG-63 osteosarcoma viability after 30days. This study successfully characterized this composite series, and demonstrated their potential for anti-cancerous applications.

Topics: Antineoplastic Agents; Biocompatible Materials; Bone Neoplasms; Carboxymethylcellulose Sodium; Cell Line, Tumor; Cell Survival; Dextrans; Gallium; Glass; Humans; Hydrogels; Osteosarcoma

Docetaxel (DTX) remains the only effective drug for prolonging survival and improving quality of life of metastatic castration resistant prostate cancer (mCRPC) patients. Despite some clinical successes with DTX-based therapies, advent of cumulative toxicity and development of drug resistance limit its long-term clinical application. The integration of nanotechnology for drug delivery can be exploited to overcome the major intrinsic limitations of DTX therapy for mCRPC. We evaluated whether reformulation of DTX by facile conjugation to carboxymethylcellulose nanoparticles (Cellax) can improve the efficacy and safety of the drug in s.c. and bone metastatic models of CRPC. A single dose of the nanoparticles completely regressed s.c. PC3 tumor xenografts in mice. In addition, Cellax elicited fewer side effects compared to native DTX. Importantly, Cellax did not increase the expression of drug resistance molecules in androgen-independent PC3 prostate cancer cells in comparison with DTX. Lastly, in a bone metastatic model of CRPC, Cellax treatment afforded a 2- to 3-fold improvement in survival and enhancements in quality-of-life of the animals over DTX and saline controls. These results demonstrate the potential of Cellax in improving the treatment of mCRPC.

Topics: Animals; Antineoplastic Agents; ATP Binding Cassette Transporter, Subfamily B, Member 1; Bone Neoplasms; Carboxymethylcellulose Sodium; Cell Line, Tumor; Docetaxel; Drug Carriers; Gene Expression; Humans; Male; Mice, Inbred BALB C; Nanoparticles; Particle Size; Prostatic Neoplasms, Castration-Resistant; Surface Properties; Survival Analysis; Taxoids; Xenograft Model Antitumor Assays

Polyinosinic-polycytidylic acid, a double-stranded ribonucleic acid that is a potent inducer of interferon production, was used in a stabilized form to treat 11 patients with metastatic renal cell carcinoma. Seven patients completed a full course of 8 infusions at maximum tolerated dosage. All patients experienced transient fever and marked fatigue. Anorexia was mild. Transient leukopenia occurred in 3 patients and reversible elevation in creatinine was observed in 1. All 4 patients with brain metastases became lethargic, and 3 died during or shortly after therapy. Only 2 patients demonstrated measurable total regression of isolated metastases (pleural/pulmonary in 1 and bone in 1) but in both metastases at other sites progressed. No partial regressions were seen. Metastases at all other sites (liver, brain and renal fossa) progressed during therapy. Patients who appeared to respond and who performed best during therapy generally demonstrated a higher performance status initially. Expression of natural cytotoxicity in in vitro testing did not correlate with a demonstrated response to treatment.

Topics: Bone Neoplasms; Brain Neoplasms; Carboxymethylcellulose Sodium; Carcinoma, Renal Cell; Humans; Interferon Inducers; Kidney Neoplasms; Lung Neoplasms; Methylcellulose; Poly I-C; Polylysine