Nanostructured Lipid Carrier-Based Gel for Repurposing Simvastatin in Localized Treatment of Breast Cancer: Formulation Design, Development, and In Vitro and In Vivo Characterization.

Simvastatin (SMV) is noticed as a repurposed candidate to be effective against breast cancer (BC). However, poor solubility, dose-limiting toxicities, and side effects are critical hurdles in its use against BC. The above drawbacks necessitate the site-specific (localized) delivery of SMV via suitable nanocarriers. Therefore, the present study intended to develop SMV nanostructured lipid carrier (NLC)-based gel using carbopol-934 as a gelling agent to achieve local delivery and improve patient compliance while combating BC. The SMV NLCs were fabricated by melt-emulsification ultrasonication technique using stearic acid as solid lipid, olive oil (OO) as liquid lipid, tween 20 as a surfactant, and PEG-200 as a co-surfactant, and optimized by Box-Behnken design. The optimized SMV-loaded NLCs displayed % entrapment efficiency of 91.66 ± 5.2% and particle size of 182 ± 11.9 nm. The pH of NLC-based gels prepared using a 2.0% w/v of carbopol-934 was found in the range of 5.3-5.6 while the viscosity was in the range of 5.1-6.6 Pa.S. Besides, NLC-based gels exhibited higher and controlled SMV release (71-76%) at pH 6.8 and (78-84%) at pH 5.5 after 48 h than SMV conventional gel (37%) at both pH 6.8 and 5.5 after 48 h. The ex vivo permeation of SMV from NLC-based gel was 3.8 to 4.5 times more than conventional gel. Notably, SMV-loaded NLCs displayed ameliorated cytotoxicity than plain SMV against MCF-7 and MDA-MB-231 BC cells. No substantial difference was noticed in the cytotoxicity of NLC-based gels and pure SMV against both cell lines. The SMV NLC-based gel exhibited the absence of skin irritation in vivo in the mice following topical application. In addition, the histopathological study revealed no alteration in the mice skin anatomy. Furthermore, the SMV-loaded NLCs and NLC-based gels were stable for 6 months at refrigerator conditions (4°C ± 2°C). Thus, the present research confirms that NLC-based gel can be a safe, efficacious, and novel alternative to treat BC.

Podophyllotoxin-polyacrylic acid conjugate micelles: improved anticancer efficacy against multidrug-resistant breast cancer.

BACKGROUND: Podophyllotoxin (PPT) is a naturally occurring compound obtained from the roots of Podophyllum species, indicated for a variety of malignant tumors such as breast, lung, and liver tumors. This toxic polyphenol (PPT) exhibited significant activity against P-glycoprotein (P-gp) mediated multidrug-resistant (MDR) cancer cells. However, extremely poor water solubility, a narrow therapeutic window, and high toxicity have greatly restricted the clinical uses of PPT. Therefore, the present research was aimed to synthesize the water-soluble ester prodrug of PPT with polyacrylic acid (PAA), a water-soluble polymer by Steglich esterification reaction, and to screen it for assay, solubility, in vitro hemolysis, in vitro release, and in vitro anticancer activity. RESULTS: The Fourier transform infrared (FTIR) and nuclear magnetic resonance (NMR) spectroscopy results revealed the successful synthesis of podophyllotoxin-polyacrylic acid conjugate (PPC). The assay and saturation solubility of the prodrug is found to be 64.01 ± 4.5% and 1.39 ± 0.05 mg/mL (PPT equivalent) respectively. The PPC showed CMC (critical micelle concentration) of 0.430 mg/mL in distilled water at room temperature. The PPC micelles showed a mean particle size of 215 ± 11 nm with polydispersity index (PDI) of 0.193 ± 0.006. Further, the transmission electron microscope (TEM) results confirmed the self-assembling character of PPC into micelles. The PPC caused significantly less hemolysis (18.6 ± 2.9%) than plain PPT solution. Also, it demonstrated significantly (p < 0.01) higher in vitro cytotoxicity against both sensitive as well as resistance human breast cancer cells (MCF-7 and MDA MB-231) after 48 h of treatment. CONCLUSION: The obtained study results clearly revealed the notable in vitro anticancer activity of PPT following its esterification with PAA. However, further in vivo studies are needed to ascertain its efficacy against a variety of cancers.

Polymeric Mixed Micelles: Improving the Anticancer Efficacy of Single-Copolymer Micelles.

Mixed micelles self-assembled from two or more dissimilar block copolymers provide a direct and convenient approach to improved drug delivery. The present review is focused on mixed micelles (prepared from block copolymers only) for various drug delivery applications along with their merits over single-copolymer micelles. Presented are the physicochemical properties of mixed and single-copolymer micelles, various stimuli-responsive mixed micelles for the treatment of cancer, interesting combinations of multifunctional mixed micelles along with their in vitro and in vivo performance, and the potential of mixed micelles as a gene delivery system. Finally, the performance of mixed micelles in preclinical and clinical testing is explained. In addition, the interaction of mixed micelles with cancer cells and the biosafety of mixed micelles are summarized. The in vitro and in vivo performance presented here clearly reveals that the mixed-micelle approach has a wider scope than that of the single-copolymer micelle approach and directs researchers to focus on this approach to delivery of drugs/gene/biologics for various applications.

Polymeric Mixed Micelles: Improving the Anticancer Efficacy of Single-Copolymer Micelles.

Mixed micelles self-assembled from two or more dissimilar block copolymers provide a direct and convenient approach to improved drug delivery. The present review is focused on mixed micelles (prepared from block copolymers only) for various drug delivery applications along with their merits over single-copolymer micelles. Presented are the physicochemical properties of mixed and single-copolymer micelles, various stimuli-responsive mixed micelles for the treatment of cancer, interesting combinations of multifunctional mixed micelles along with their in vitro and in vivo performance, and the potential of mixed micelles as a gene delivery system. Finally, the performance of mixed micelles in preclinical and clinical testing is explained. In addition, the interaction of mixed micelles with cancer cells and the biosafety of mixed micelles are summarized. The in vitro and in vivo performance presented here clearly reveals that the mixed-micelle approach has a wider scope than that of the single-copolymer micelle approach and directs researchers to focus on this approach to delivery of drugs/gene/biologics for various applications.

Mixed Micelles as Nano Polymer Therapeutics of Docetaxel: Increased In vitro Cytotoxicity and Decreased In vivo Toxicity.

BACKGROUND: Docetaxel (DTX) has been used to treat several types of cancers, but it has provided pharmaceutical challenges due to its poor water solubility and toxicities associated with the co-solvents (tween-80 and ethanol). Nanopolymer therapeutics can be engineered to deliver anticancer agent specifically to cancer cells, thereby leaving normal healthy cells unaffected by toxic drugs such as DTX. The objective of the present study was to synthesize the polyacrylic acid (PAA)-DTX conjugate (PAADC) and preparation of nanopolymer therapeutics such as PAADC/DSPE-mPEG2000 mixed micelles (PAADC-DP MMs). METHODS: The prepared PAADC-DP MMs were characterized for mean particle size and zeta potential, in vitro release profile using dialysis technique, hemolytic behavior against human blood, and cytotoxicity against human cancer cell line (A549) using MTT assay. In vivo acute toxicity of PAADC-DP MMs was determined in albino mice at intravenous single dose of 40 mg/kg. RESULTS: PAADC-DP MMs showed mean particle size of 443±9nm. PAADC-DP MMs showed maximum DTX loading (DTX equivalent; 90.5±2.7%) with minimum DSPE-mPEG2000 molecules (1:1 ratio), while to load 77.9±2.2% of plain DTX, more DSPE-mPEG2000 is required(1:10 ratio). The developed PAADC-DP MMs system showed significantly lower CMC (5 ng/mL), sustained release profile (28.6±1.9% after 48 h of study), lower hemolytic behavior (13.7±1.3% of hemolysis ratio at 40 µg/mL concentration and after 1 h incubation), higher in vitro cytotoxicity (IC50 of 0.0064±0.001 nM after 48 h study) and remarkably reduced in vivo toxicity (9.9±2.1% body weight loss) in mice when compared to marketed Taxotere®. CONCLUSION: The obtained results clearly demonstrated that the developed PAADC-DP MMs system is a promising approach for cancer chemotherapy with reduced toxicity.

Pulmonary multifunctional nano-oncological modules for lung cancer treatment and prevention.

Mortality associated with lung cancer and its metastasis has outnumbered those related to other forms of cancer. Despite being a directly accessible organ, conventional oncological strategies exhibiting prolific outcome in treatment and prevention of lung cancer is far from reality. This is attributed to numerous challenges posed by lung environment. The extracellular aura of lung comprises immensely complicated structures, ciliary escalators, omnipresence of mucus and alveolar fluid, and macrophagial uptake which presents an array of impediments to the arrival of therapeutic moiety at the tumor site. Besides these, intracellular obstacles viz enzymatic degradation, cell membrane translocation, endosomal escape and/or nuclear entry also limit superior therapeutic efficacy. The current review elaborates wide-ranging challenges to lung cancer treatment and its circumvention by latest developments in multifunctional nano-oncological modules delivered via the pulmonary route-which smartly deal with the abovementioned issues and bestow positivity to this complication.