Exposure to Dichlorvos pesticide alters the morphology of and lipid metabolism in the ventral prostate of rats

Organophosphate pesticides are widely used in agriculture, leading to soil, water, and food contamination. Among these compounds is Dichlorvos [O,O-dimethyl O-(2,2-dichlorovinyl)phosphate, DDVP], which is listed as a highly toxic compound by the Environmental Protection Agency and World Health Organization. Exposure to DDVP can result in nervous, respiratory, hepatic, and reproductive abnormalities, in addition to endocrine disrupting, mutagenic, and carcinogenic effects. Little is known about the impacts of DDVP on the reprogramming of lipid metabolism, which is also associated with the development and progression of cancer, since the tumor cells need to recruit, capture, and use fatty acids to compose their building membranes. This study aimed to evaluate the influence of the pesticide DDVP on lipid metabolism in the prostate, after chemical induction by the carcinogen N-methyl-N-nitrosourea (MNU). For this, 32 Fischer rats aged 90 days were randomly divided into four experimental groups: Control, DDVP, MNU, and MNU + DDVP. The MNU and MNU + DDVP groups underwent chemical induction with MNU (15 mg/kg) and the DDVP and MNU + DDVP groups received a diet supplemented with DDVP (10 mg/kg). Histopathological analyses of the rat ventral prostate showed 100% incidence of epithelial hyperplasia in the MNU and MNU + DDVP groups. This finding was accompanied by an increase of the epithelial compartment in the MNU + DDVP group. Immunolocalization of important proteins linked to lipid metabolism has been established. In the MNU + DDVP group, Western blotting analyses pointed out an increased expression of the protein LIMP II (Lysosomal Integral Membrane Protein-II), which is correlated with the capture and distribution of lipids in tumor cells. Together, these results indicate that the association of a low dose of DDVP with MNU was able to promote alterations in the morphology and lipid metabolism of the rat ventral prostate, which may be related to tumor progression in this organ.

Combinatorial approaches of nanotherapeutics for inflammatory pathway targeted therapy of prostate cancer

Prostate cancer (PC) is the most prevalent male urogenital cancer worldwide. PC patients presenting an advanced or metastatic cancer succumb to the disease, even after therapeutic interventions including radiotherapy, surgery, androgen deprivation therapy (ADT), and chemotherapy. One of the hallmarks of PC is evading immune surveillance and chronic inflammation, which is a major challenge towards designing effective therapeutic formulations against PC. Chronic inflammation in PC is often characterized by tumor microenvironment alterations, epithelial-mesenchymal transition and extracellular matrix modifications. The inflammatory events are modulated by reactive nitrogen and oxygen species, inflammatory cytokines and chemokines. Major signaling pathways in PC includes androgen receptor, PI3K and NF-κB pathways and targeting these inter-linked pathways poses a major therapeutic challenge. Notably, many conventional treatments are clinically unsuccessful, due to lack of targetability and poor bioavailability of the therapeutics, untoward toxicity and multidrug resistance. The past decade witnessed an advancement of nanotechnology as an excellent therapeutic paradigm for PC therapy. Modern nanovectorization strategies such as stimuli-responsive and active PC targeting carriers offer controlled release patterns and superior anti-cancer effects. The current review initially describes the classification, inflammatory triggers and major inflammatory pathways of PC, various PC treatment strategies and their limitations. Subsequently, recent advancement in combinatorial nanotherapeutic approaches, which target PC inflammatory pathways, and the mechanism of action are discussed. Besides, the current clinical status and prospects of PC homing nanovectorization, and major challenges to be addressed towards the advancement PC therapy are also addressed.

Advances in the therapeutic delivery and applications of functionalized Pluronics: A critical review

Pluronic (PEO-PPO-PEO) block copolymers can form nano-sized micelles with a structure composed of a hydrophobic PPO core and hydrophilic PEO shell layer. Pluronics are U.S. Food and Drug Administration approved polymers, which are widely used for solubilization of drugs and their delivery, gene/therapeutic delivery, diagnostics, and tissue engineering applications due to their non-ionic properties, non-toxicity, micelle forming ability, excellent biocompatibility and biodegradability. Although Pluronics have been employed as drug carrier systems for several decades, numerous issues such as rapid dissolution, shorter residence time in biological media, fast clearance and weak mechanical strength have hindered their efficacy. Pluronics have been functionalized with pH-sensitive, biological-responsive moieties, antibodies, aptamers, folic acid, drugs, different nanoparticles, and photo/thermo-responsive hydrogels. These functionalization strategies enable Pluronics to act as stimuli responsive and targeted drug delivery vehicles. Moreover, Pluronics have emerged in nano-emulsion formulations and have been utilized to improve the properties of cubosomes, dendrimers and nano-sheets, including their biocompatibility and aqueous solubility. Functionalization of Pluronics results in the significant improvement of target specificity, loading capacity, biocompatibility of nanoparticles and stimuli responsive hydrogels for the promising delivery of a range of drugs. Therefore, this review presents an overview of all advancements (from the last 15 years) in functionalized Pluronics, providing a valuable tool for industry and academia in order to optimize their use in drug or therapeutic delivery, in addition to several other biomedical applications.

Silica-Based Nanoparticles as Drug Delivery Vehicles for Prostate Cancer Treatment

Prostate cancer (PCa) is one of the most commonly diagnosed cancers and is the fifth common cause of cancer-related mortality in men. Current methods for PCa treatment are insufficient owing to the challenges related to the non-specificity, instability and side effects caused by the drugs and therapy agents. These drawbacks can be mitigated by the design of a suitable drug delivery system that can ensure targeted delivery and minimise side effects. Silica based nanoparticles (SBNPs) have emerged as one of the most versatile materials for drug delivery due to their tunable porosities, high surface area and tremendous capacity to load various sizes and chemistry of drugs. This review gives a brief overview of the diagnosis and current treatment strategies for PCa outlining their existing challenges. It critically analyzes the design, development and application of pure, modified and hybrid SBNPs based drug delivery systems in the treatment of PCa, their advantages and limitations.

Doxorubicin-Functionalized Silica Nanoparticles Incorporated into a Thermoreversible Hydrogel and Intraperitoneally Administered Result in High Prostate Antitumor Activity and Reduced Cardiotoxicity of Doxorubicin

Described here is an anticancer material based on colloidal mesoporous silica nanoparticles (MSNs) functionalized with doxorubicin (DOX), and incorporated into Pluronic F127 hydrogels for prolonged release, with a potential therapeutic application for prostate cancer treatment. The MSNs have spherical morphology, size of about 60 nm, surface area of 970 cm² g^-1 and average pore width of 2.0 nm. A high colloidal stability for the MSNs in the physiological medium used for in vivo administration (NaCl 0.9% w/v) could be attained in the presence of PF127 (from 5 to 18 wt %), where depletion repulsion forces prevent MSN agglomeration. By conjugating DOX, MSN and PF127 (18 wt %) in NaCl 0.9%, the hybrid system has a gelation temperature of 21 °C, which allowed its in vivo administration in the liquid form and further in situ gelation, generating a drug depot system inside the animals after peritoneal injection. The systems were tested in rats with chemically induced prostate cancer and, after this treatment, histopathological analyses confirmed (i) a reduction in the frequency of aggressive tumors; (ii) that the antitumor effect was dependent on MSN concentration; and most importantly (iii) the reduction of DOX intrinsic cardiotoxicity, indicating that the MSNs play a cardioprotective effect.