Auranofin-Loaded Chitosan Nanoparticles Demonstrate Potency against Triple-Negative Breast Cancer.

Triple-negative breast cancer (TNBC) remains a clinical challenge due to molecular, metabolic, and genetic heterogeneity as well as the lack of validated drug targets. Thus, therapies or delivery paradigms are needed. Gold-derived compounds including the FDA-approved drug, auranofin have shown promise as effective anticancer agents against several tumors. To improve the solubility and bioavailability of auranofin, we hypothesized that the nanodelivery of auranofin using biodegradable chitosan modified polyethylene glycol (PEG) nanoparticles (NPs) will enhance anticancer activity against TNBC by comparing the best nanoformulation with the free drug. The selection of the nanoformulation was based on synthesis of various chitosan PEG copolymers via formaldehyde-mediated engraftment of PEG onto chitosan to form [chitosan-g-PEG] copolymer. Furthermore, altered physiochemical properties of the copolymer was based on the formaldehyde ratio towards nanoparticles (CP 1-4 NPs). Following the recruitment of PEG onto the chitosan polymer surface, we explored how this process influenced the stiffness of the nanoparticle using atomic force microscopy (AFM), a factor crucial for in vitro and in vivo studies. Our objective was to ensure the full functionality and inherent properties of chitosan as the parent polymer was maintained without allowing PEG to overshadow chitosan's unique cationic properties while improving solubility in neutral pH. Hence, CP 2 NP was chosen. To demonstrate the efficacy of CP 2 NP as a good delivery carrier for auranofin, we administered a dose of 3 mg/kg of auranofin, in contrast to free auranofin, which was given at 5 mg/kg. In vivo studies revealed the potency of encapsulated auranofin against TNBC cells with a severe necrotic effect following treatment superior to that of free auranofin. In conclusion, chitosan-g-PEG nanoparticles have the potential to be an excellent delivery system for auranofin, increasing its effectiveness and potentially reducing its clinical limitations.

Zwitterionic amino acid-based Poly(ester urea)s suppress adhesion formation in a rat intra-abdominal cecal abrasion model.

Hernia repair outcomes have improved with more robust material options for surgeons and optimized surgical techniques. However, ventral hernia repairs remain challenging with an inherent risk of post-surgical adhesions in the peritoneal space which can occur regardless of interventional material or its surgical placement. Herein, amino acid-based poly(ester urea)s (PEUs) with varied amount of an allyl ether side chains were modified post polymerization modification with the zwitterionic sulfnate group (3-((3-((3-mercaptopropanoyl)oxy)propyl) dimethylammonio)propane-1-sulfonate) to promote anti-adhesive properties. These alloc-PEUs were processed using roll-to-roll fabrication methods to afford films that were amenable to surface functionalization via a zwitterion-thiol. Functional group availability on the surface was confirmed via fluorescence microscopy, x-ray photoelectron spectroscopy (XPS), and quartz crystal microbalance (QCM) measurements. Zwitterionic treated PEUs exhibited reduced fibrinogen adsorption in vitro when compared to unfunctionalized control polymer. A rat intrabdominal cecal abrasion adhesion model was used to assess the extent and tenacity of adhesion formation in the presence of the PEUs. The 10% alloc-PEU zwitterion functionalized material was found to reduce the extent and tenacity of adhesions when compared to adhesion controls and the unfunctionalized PEU controls.

Dual Carfilzomib and Doxorubicin-Loaded Liposomal Nanoparticles for Synergistic Efficacy in Multiple Myeloma.

Here, we report the synthesis and evaluation of dual drug-loaded nanoparticles as an effective means to deliver carfilzomib and doxorubicin to multiple myeloma tumor cells at their optimal synergistic ratio. First, various molar ratios of carfilzomib to doxorubicin were screened against multiple myeloma cell lines to determine the molar ratio that elicited the greatest synergy using the Chou-Talalay method. The therapeutic agents were then incorporated into liposomes at the optimal synergistic ratio of 1:1 to yield dual drug-loaded nanoparticles with a narrow size range of 115 nm and high reproducibility. Our results demonstrated that the dual drug-loaded liposomes exhibited synergy in vitro and were more efficacious in inhibiting tumor growth in vivo than a combination of free drugs, while at the same time reducing systemic toxicity. Taken together, this study presents the synthesis and preclinical evaluation of dual drug-loaded liposomes containing carfilzomib and doxorubicin for enhanced therapeutic efficacy to improve patient outcome in multiple myeloma. Mol Cancer Ther; 15(7); 1452-9. ©2016 AACR.

Liposomal bortezomib nanoparticles via boronic ester prodrug formulation for improved therapeutic efficacy in vivo.

In this study, we describe the development of liposomal bortezomib nanoparticles, which was accomplished by synthesizing bortezomib prodrugs with reversible boronic ester bonds and then incorporating the resulting prodrugs into the nanoparticles via surface conjugation. Initially, several prodrug candidates were screened based upon boronic ester stability using isobutylboronic acid as a model boronic acid compound. The two most stable candidates were then selected to create surface conjugated bortezomib prodrugs on the liposomes. Our strategy yielded stable liposomal bortezomib nanoparticles with a narrow size range of 100 nm and with high reproducibility. These liposomal bortezomib nanoparticles demonstrated significant proteasome inhibition and cytotoxicity against multiple myeloma cell lines in vitro and remarkable tumor growth inhibition with reduced systemic toxicity compared to free bortezomib in vivo. Taken together, this study demonstrates the incorporation of bortezomib into liposomal nanoparticles via reversible boronic ester bond formation to enhance the therapeutic index for improved patient outcome.

Liposomal carfilzomib nanoparticles effectively target multiple myeloma cells and demonstrate enhanced efficacy in vivo.

Carfilzomib, a recently FDA-approved proteasome inhibitor, has remarkable anti-myeloma (MM) activity. However, its effectiveness is limited by associated severe side-effects, short circulation half-life, and limited solubility. Here, we report the engineering of liposomal carfilzomib nanoparticles to overcome these problems and enhance the therapeutic efficacy of carfilzomib by increasing tumoral drug accumulation while decreasing systemic toxicity. In our design, carfilzomib was loaded into the bilayer of liposomes to yield stable and reproducible liposomal nanoparticles. Liposomal carfilzomib nanoparticles were efficiently taken up by MM cells, demonstrated proteasome inhibition, induced apoptosis, and exhibited enhanced cytotoxicity against MM cells. In vivo, liposomal carfilzomib demonstrated significant tumor growth inhibition and dramatically reduced overall systemic toxicity compared to free carfilzomib. Finally, liposomal carfilzomib demonstrated enhanced synergy in combination with doxorubicin. Taken together, this study establishes the successful synthesis of liposomal carfilzomib nanoparticles that demonstrates improved therapeutic index and the potential to improve patient outcome in MM.

Bupivacaine-enhanced small intestinal submucosa biomaterial as a hernia repair device.

Management of post-surgical pain following herniorrhaphy remains a clinical challenge and novel methods to deliver analgesic compounds could be of great benefit. Because there is great interest in the use of natural biomaterials for hernia repair, we investigated the biocompatibility of a natural biomaterial, porcine small intestinal submucosa (SIS), which was impregnated with bupivacaine (SIS-B) via immersion in a solution of poly(lactic-co-glycolic acid) (PLGA). Groups of Sprague Dawley rats underwent surgical creation of a ventral abdominal wall defect with subsequent repair using either SIS or SIS-B. Analysis of serial blood samples showed peak bupivacaine levels (83 ng/mL) were achieved 16 h after implantation of SIS-B. One month after surgery, the rats were euthanized and implant sites harvested for mechanical strength testing and histological analysis. At the time of necropsy, adhesion extent and tenacity was greater in SIS-B rats, with 90% of SIS-B rats have adhesion to the implant site compared to only 75% of SIS rats. Microscopically, SIS implant sites were characterized by small amounts of residual SIS surrounded by mild-to-moderate chronic inflammation. In contrast, rats treated with SIS-B, residual SIS-B was surrounded by a ring of acute inflammatory cells and an outer ring of chronic inflammatory cells, possibly due to bupivacaine or residual PLGA. Mechanical strength testing of the harvested implant sites showed no significant (p ≤ 0.05) difference between SIS and SIS-B implants. In summary, bupivacaine is readily elaborated from SIS-B; and impregnation of SIS with bupivacaine does not substantially alter the biocompatibility of the biomaterial or its mechanical strength following implantation.

Addition of nimesulide to small intestinal submucosa biomaterial inhibits postsurgical adhesiogenesis in rats.

Adhesion formation is a common complication in abdominal surgery with incidence as high as 93% and small bowel obstruction a common complication. Because the extracellular matrix material, small intestinal submucosa (SIS), is commonly used in various surgical procedures, methods to inhibit adhesiogenesis are of great interest. This study was undertaken to determine if incorporation of nimesulide (NM), a selective cyclooxygenase (COX)-2 inhibitor, could reduce the extent and tenacity of intraabdominal adhesion formation associated with SIS implantation. Female Sprague-Dawley rats underwent a cecal abrasion surgical procedure to induce adhesiogenesis. Rats were either left untreated or treated by direct application over the injured cecum with polypropylene mesh (PPM); SIS; SIS containing a low dose of NM; or SIS containing a high dose of NM. Rats were euthanized 21 days later, and adhesion extent and tenacity were evaluated using standard scales (0 = minimal adhesiogenesis; 4 = severe adhesiogenesis). Addition of NM to SIS resulted in a significant (p < 0.05) reduction in adhesion extent and in a similar reduction in adhesion tenacity for SIS containing a low dose of NM. Adhesions typically extended from the abraded cecal surface to the body wall and were characterized histologically by fibrous tissue adherent to the cecal wall. In conclusion, addition of the nonsteroidal anti-inflammatory, COX-2 selective drug, NM, to SIS attenuates adhesion extent and tenacity when compared with surgical placement of SIS or PPM alone.

Small intestinal submucosa does not promote PAIII tumor growth in Lobund-Wistar rats.

BACKGROUND: Site-specific remodeling and angiogenesis are two observations associated with the use of small intestinal submucosa (SIS) as a tissue repair graft. Its angiogenic capacity has raised questions concerning its effect on tumor growth and metastasis in clinical tumor resection cases. The effect of SIS on the ability of neoplastic (prostate adenocarcinoma) cells to establish, grow, and metastasize was examined in Lobund-Wistar (L-W) rats. MATERIALS AND METHODS: In one study, SIS, expanded polytetrafluoroethylene (ePTFE), or human cadaveric dermis was placed in a subcutaneous pocket on the flank of L-W rats and immediately inoculated with PA-III cell suspension. Tumors were allowed to establish and metastasize for 5 weeks prior to sacrifice. Rate of tumor growth, tumor weight, and frequency of lung metastases were assessed. In a second study, SIS was placed in a resected tumor bed and tumors were allowed to recur. Rate of tumor growth, tumor weight, and frequency of lung metastases were assessed after 3 weeks. RESULTS: ePTFE hastened the rate of formation of palpable tumors compared to controls and other materials; cadaveric dermis and SIS did not. No differences between materials were noted in final tumor weight nor in the frequency of metastasis to the lungs. Following surgical tumor resection, residual tumor cells led to recurrence of same-site tumors in all animals, but in the defects augmented with SIS, the tumors were significantly smaller than those which regrew in the resected, unaugmented group. CONCLUSIONS: This study demonstrates that SIS does not enhance tumor establishment, growth, or metastasis in de novo tumors. Furthermore, SIS appears to reduce the rate of tumor growth, but not metastasis, when applied in direct contact with a residual tumor bed in a rat model of prostate-related tumors.