Prostate cancer chemotherapy by intratumoral administration of Docetaxel-Mesoporous silica nanomedicines

Docetaxel (DTX) is a recommended treatment in patients with metastasic prostate cancer (PCa), despite its therapeutic efficacy is limited by strong systemic toxicity. However, in localized PCa, intratumoral (IT) administration of DTX could be an alternative to consider that may help to overcome the disadvantages of conventional intravenous (IV) therapy. In this context, we here present the first in vivo preclinical study of PCa therapy with nanomedicines of mesoporous silica nanoparticles (MSN) and DTX by IT injection over a xenograft mouse model bearing human prostate adenocarcinoma tumors. The efficacy and tolerability, the biodistribution and the histopathology after therapy have been investigated for the DTX nanomedicine and the free drug, and compared with the IV administration of DTX. The obtained results demonstrate that IT injection of DTX and DTX nanomedicines allows precise and selective therapy of non-metastatic PCa and minimize systemic diffusion of the drug, showing superior activity than IV route. This allows reducing the therapeutic dose by one order and widens substantially the therapeutic window for this drug. Furthermore, the use of DTX nanomedicines as IT injection promotes strong antitumor efficacy and drug accumulation at the tumor site, improving the results obtained with the free drug by the same route.

Changes in the content of Puerarin-PLGA nanoparticles in mice under the influence of alcohol and analysis of their antialcoholism

To observe the metabolic changes and antialcoholic effect of Puerarin-PLGA nanoparticles (PUE-NP) in mice. PUE-NP was prepared and characterized by particle size distribution and morphology. The mouse models with acute alcoholism were established to observe their behavioral changes after alcohol poisoning. The expressions of biologically active enzymes such as CRE, BUN, AST, ALT in serum and SOD and TLR4 in liver of mice in each group were detected, and the pathological changes in liver and kidney tissues were observed by HE staining. The PUE-NP metabolism in mice was determined by in vitro release assay and HPLC. PUE-NP nanoparticles had good morphology and structure, and the mouse models with alcohol poisoning were established successfully. Compared with alcohol group, puerarin and PUE-NP increased the disappearance latency time of righting reflex, and the recovery time of righting reflex was significantly shortened. Water maze results showed that Puerarin and PUE-NP had inhibitory effect on impaired memory. HPLC results showed that PUE-NP reached its peak in mice after 1 h, and the content percentage was twice that of puerarin preparation alone, and the distribution time of puerarin concentration in vivo was prolonged, indicating that PLGA nanoparticles had a loading and slow-release effect on puerarin and increased the bioavailability of puerarin in mice. In addition, compared with the alcohol group, Puerarin and PUE-NP improved serum ALT, AST, CRE, and BUN levels in mice, enhanced SOD activity in liver, and inhibited TLR4 expression. The effect was better in the PUE-NP group than in the Puerarin group. PUE-NP delayed the release and metabolism of Puerarin and had better effect in the treatment of the alcoholic liver and kidney injury.

Critical Review of Biodegradable and Bioactive Polymer Composites for Bone Tissue Engineering and Drug Delivery Applications

In the determination of the bioavailability of drugs administered orally, the drugs' solubility and permeability play a crucial role. For absorption of drug molecules and production of a pharmacological response, solubility is an important parameter that defines the concentration of the drug in systemic circulation. It is a challenging task to improve the oral bioavailability of drugs that have poor water solubility. Most drug molecules are either poorly soluble or insoluble in aqueous environments. Polymer nanocomposites are combinations of two or more different materials that possess unique characteristics and are fused together with sufficient energy in such a manner that the resultant material will have the best properties of both materials. These polymeric materials (biodegradable and other naturally bioactive polymers) are comprised of nanosized particles in a composition of other materials. A systematic search was carried out on Web of Science and SCOPUS using different keywords, and 485 records were found. After the screening and eligibility process, 88 journal articles were found to be eligible, and hence selected to be reviewed and analyzed. Biocompatible and biodegradable materials have emerged in the manufacture of therapeutic and pharmacologic devices, such as impermanent implantation and 3D scaffolds for tissue regeneration and biomedical applications. Substantial effort has been made in the usage of bio-based polymers for potential pharmacologic and biomedical purposes, including targeted deliveries and drug carriers for regulated drug release. These implementations necessitate unique physicochemical and pharmacokinetic, microbiological, metabolic, and degradation characteristics of the materials in order to provide prolific therapeutic treatments. As a result, a broadly diverse spectrum of natural or artificially synthesized polymers capable of enzymatic hydrolysis, hydrolyzing, or enzyme decomposition are being explored for biomedical purposes. This summary examines the contemporary status of biodegradable naturally and synthetically derived polymers for biomedical fields, such as tissue engineering, regenerative medicine, bioengineering, targeted drug discovery and delivery, implantation, and wound repair and healing. This review presents an insight into a number of the commonly used tissue engineering applications, including drug delivery carrier systems, demonstrated in the recent findings. Due to the inherent remarkable properties of biodegradable and bioactive polymers, such as their antimicrobial, antitumor, anti-inflammatory, and anticancer activities, certain materials have gained significant interest in recent years. These systems are also actively being researched to improve therapeutic activity and mitigate adverse consequences. In this article, we also present the main drug delivery systems reported in the literature and the main methods available to impregnate the polymeric scaffolds with drugs, their properties, and their respective benefits for tissue engineering.

A robust systematic design: Optimization and preparation of polymeric nanoparticles of PLGA for docetaxel intravenous delivery

Poly (lactide-co-glycolide) (PLGA) is a biocompatible, biodegradable, and non-toxic polymer used in a variety of biomedical and pharmaceutical applications. Polymeric nanoparticles prepared from PLGA have been extensively used as delivery vehicles of various chemotherapeutic agents. The variability of PLGA polymer and nanoparticle fabrication process potentially results in variability of particle characteristics. Nanoparticle characteristics determine nanoparticles' performance when used as drug delivery systems. Having control on nanoparticle's characteristics grants control over the fate of nanoparticles and the associated drug. Here, L16 Taguchi experimental design was used to evaluate the effect of polymer characteristics and fabrication variables on PLGA nanoparticles. The design was used to determine an optimized preparation condition for PLGA nanoparticles as an intravenous delivery system for docetaxel. An emulsification-solvent-evaporation method was used to fabricate nanoparticles. Docetaxel concentration, organic phase:aqueous phase ratio, polymer molecular weight, polymer terminus, lactide:glycolide ratio, and Poly(vinyl alcohol)(PVA) concentration were selected as main determinants. First two factors were evaluated at 4 levels and the rest at 2 levels. Particle-important characteristics including size, polydispersity index (PDI), surface charge (zeta potential), and docetaxel loading-efficiency were determined. Factors affecting nanoparticle characteristics were ranked according to level of effectiveness. Factors that affected nanoparticle properties with statistical significance were identified. Models to predict nanoparticle characteristics were built. An optimized fabrication method was identified and used to prepare PLGA nanoparticles for docetaxel delivery.

Determination of total and unbound docetaxel in plasma by ultrafiltration and UPLC-MS/MS: application to pharmacokinetic studies

A sensitive and specific liquid chromatographic/tandem mass spectrometric (LC-MS/MS) method was developed and validated for quantifying total and unbound docetaxel drug concentrations in plasma. Calibration curves for unbound and total docetaxel were linear over the respective ranges of 0.108~10.8 and 0.54~216 ng/mL. The intra- and interday assay accuracy and precision did not exceed 15%. The methods were validated to show the standard range linearity, sensitivity, selectivity, accuracy, precision, and stability of docetaxel in the matrices tested. In addition, this method is fast and simple with a short run time of 4.5 min and a small plasma sample volume (500 µL). The validated method was successfully applied to a pharmacokinetic study of a docetaxel micelle formulation in rat plasma after intravenous administration at a dose of 10 mg/kg. Docetaxel micelles slowly released their drug payload, and protein-bound, unbound, and micellar drug pools existed simultaneously. These various forms in plasma pools were also measured in the study. We confirmed that most of the docetaxel in plasma was micelle-associated (96.52% at 24 h and 83.14% at 72 h) after micellar docetaxel administration, as a result of sequestration of the drug in long-circulating micelles.