Lipid polymer hybrid nanoparticles: a custom-tailored next-generation approach for cancer therapeutics.

Lipid-based polymeric nanoparticles are the highly popular carrier systems for cancer drug therapy. But presently, detailed investigations have revealed their flaws as drug delivery carriers. Lipid polymer hybrid nanoparticles (LPHNPs) are advanced core-shell nanoconstructs with a polymeric core region enclosed by a lipidic layer, presumed to be derived from both liposomes and polymeric nanounits. This unique concept is of utmost importance as a combinable drug delivery platform in oncology due to its dual structured character. To add advantage and restrict one's limitation by other, LPHNPs have been designed so to gain number of advantages such as stability, high loading of cargo, increased biocompatibility, rate-limiting controlled release, and elevated drug half-lives as well as therapeutic effectiveness while minimizing their drawbacks. The outer shell, in particular, can be functionalized in a variety of ways with stimuli-responsive moieties and ligands to provide intelligent holding and for active targeting of antineoplastic medicines, transport of genes, and theragnostic. This review comprehensively provides insight into recent substantial advancements in developing strategies for treating various cancer using LPHNPs. The bioactivity assessment factors have also been highlighted with a discussion of LPHNPs future clinical prospects.

MUC1 aptamer-tethered H40-TEPA-PEG nanoconjugates for targeted siRNA-delivery and gene silencing in breast cancer cells.

With a prevalence of 12.5% of all new cancer cases annually, breast cancer stands as the most common form of cancer worldwide. The current therapies utilized for breast cancer are constrained and ineffective in addressing the condition. siRNA-based gene silencing is a promising method for treating breast cancer. We have developed an aptamer-conjugated dendritic multilayered nanoconjugate to treat breast cancer. Initially, we transformed the hydroxyl groups of the hyperbranched bis-MPA polyester dendrimer into carboxylic groups. Subsequently, we linked these carboxylic groups to tetraethylenepentamine to form a positively charged dendrimer. In addition, the mucin-1 (MUC1) aptamer was attached to the dendrimer using a heterobifunctional polyethylene glycol. Characterizing dendrimers involved 1H NMR and dynamic light scattering techniques at every production stage. A gel retardation experiment was conducted to evaluate the successful binding of siRNA with targeted and non-targeted dendrimers. The targeted dendrimers exhibited no harmful effects on the NIH-3T3 fibroblast cells and RBCs, indicating their biocompatible characteristics. Confocal microscopy demonstrated significant higher uptake of targeted dendrimers than non-targeted dendrimers in MCF-7 breast cancer cells. The real-time PCR results demonstrated that the targeted dendrimers exhibited the most pronounced inhibition of the target gene expression compared to the non-targeted dendrimers and lipofectamine-2000. The caspase activation study confirmed the functional effect of survivin silencing by dendrimer, which led to the induction of apoptosis in breast cancer cells. The findings indicated that Mucin-1 targeted hyperbranched bis-MPA polyester dendrimer carrying siRNA could successfully suppress the expression of the target gene in breast cancer cells.

Nucleolin aptamer conjugated MSNPs-PLR-PEG multifunctional nanoconstructs for targeted co-delivery of anticancer drug and siRNA to counter drug resistance in TNBC.

The emergence of drug resistance in cancer cells is among the major challenges for treating cancer. In the last few years, the co-delivery of drug and siRNA has shown promising results against drug-resistant cancers. In the present study, we developed mesoporous silica-based multifunctional nanocarrier for co-delivery against drug-resistant triple-negative breast cancer (TNBC) cells. We synthesized the nanocarrier by modifying mesoporous silica nanoparticles with poly-L-arginine, polyethylene glycol and AS1411 aptamer to impart siRNA binding ability, biocompatibility, and cancer cell specificity, respectively. We optimized the loading of doxorubicin (DOX) within the developed nanocarrier to avoid interference with siRNA binding. We ascertained the target specificity by performing a receptor blockade assay during cellular uptake studies. The cytotoxic efficacy of DOX and siRNA co-delivered using the developed nanocarrier was assessed using DOX-resistant MDA-MB-231 TNBC cells. The nanocarrier exhibited >10-fold and 40-fold reduction in the IC50 values of DOX due to co-delivery with BCl-xL and BCL-2 siRNA, respectively. The results were further validated using a 3-D in vitro cell culture system. This study demonstrates that the targeted co-delivery of drug and siRNA has a strong potential to overcome drug resistance in TNBC cells.

Challenges and emerging strategies for next generation liposomal based drug delivery: An account of the breast cancer conundrum.

The global cancer burden is witnessing an upsurge with breast cancer surpassing other cancers worldwide. Furthermore, an escalation in the breast cancer caseload is also expected in the coming years. The conventional therapeutic regimens practiced routinely are associated with many drawbacks to which nanotechnological interventions offer a great advantage. But how eminent could liposomes and their advantages be in superseding these existing therapeutic modalities? A solution is reflected in this review that draws attention to a decade-long journey embarked upon by researchers in this wake. This text is a comprehensive discussion of liposomes, the front runners of the drug delivery systems, and their active and passive targeting approaches for breast cancer management. Active targeting has been studied over the decade by many receptors overexpressed on the breast cancer cells and passive targeting with many drug combinations. The results converge on the fact that the actively targeted formulations exhibit a superior efficacy over their non-targeted counterparts and the all liposomal formulations are efficacious over the free drugs. This undoubtedly underlines the dominion of liposomal formulations over conventional chemotherapy. These investigations have led to the development of different liposomal formulations with active and passive targeting capacities that could be explored in depth. Acknowledging and getting a deeper insight into the liposomal evolution through time also unveiled many imperfections and unchartered territories that can be explored to deliver dexterous liposomal formulations against breast cancer and more in the clinical trial pipeline.

Aptamer Tethered Bio-Responsive Mesoporous Silica Nanoparticles for Efficient Targeted Delivery of Paclitaxel to Treat Ovarian Cancer Cells.

Ovarian cancer is the leading cause of cancer deaths in female patients. The current therapeutics in ovarian cancer are limited and inefficient in curing the disease. To tackle this, we have synthesized tetrasulfide derivative of silica doped, biodegradable, glutathione-responsive targeted mesoporous silica nanoparticles modified with heterobifunctional polyethylene glycol as a linker and mucin-1 aptamer for triggered paclitaxel delivery to the ovarian cancer cells. Degradable mesoporous silica nanoparticles were synthesized by a modified sol-gel method with tetraethyl orthosilicate and Bis (triethoxysilylpropyl) tetrasulfide. The degradable mesoporous silica nanoparticles were characterized by dynamic light scattering, Fourier-transform infrared spectroscopy, Scanning electron microscopy and Transmission electron microscopy. The degradable mesoporous silica nanoparticles had good paclitaxel encapsulation efficiency and glutathione-responsive paclitaxel release ability. The glutathione utilization assay and visual destruction observed within 10 days in transmission electron microscopy images confirmed the degradation of the mesoporous silica nanoparticles in the tumor cell environment. The targeted degradable mesoporous silica nanoparticles were efficiently taken up by ovarian cancer cell lines OVACAR-3 and PA-1. The cytotoxicity of bare mesoporous silica nanoparticles evaluated on NIH-3T3 cell line showed good biocompatibility (>90% cell viability). Significant toxicity on OVACAR-3 (IC50 25.66 nM) and PA-1 (IC50 42.93 nM) cell lines was observed when treated with paclitaxel-loaded targeted degradable mesoporous silica nanoparticles. Results of this study demonstrated that mucin-1 targeted, glutathione-responsive mesoporous silica nanoparticles loaded with paclitaxel had a significant antitumor effect on ovarian cancer cells. All these findings demonstrated that developed nano-formulation could be suitable for ovarian cancer treatment.

Targeted silencing of the MCL-1 gene using multi-layered dendrimer-based nanoconstructs achieves efficient tumor regression in xenografted mice models.

The setback in the practical clinical use of RNA interference (RNAi)-based cancer treatment stems from the lack of targeted small interfering RNA (siRNA) delivery. Here, we show that luteinizing hormone-releasing hormone(LHRH) analog-tethered multi-layered polyamidoamine (PAMAM) nanoconstructs silence the anti-apoptotic MCL-1 gene in LHRH receptor overexpressing human breast (MCF-7) and prostate cancer (LNCaP) cells with 70.91 % and 74.10 % efficiency, respectively. These results were confirmed by RT-PCR. The Acridine orange/Ethidium bromide (AO/EB) dual staining revealed that the silencing of MCL-1 induced apoptosis in both the cell lines. In vivo tumor regression studies performed using MCF-7 and LNCaP xenografted severe combined immunodeficiency(SCID) mice demonstrated highly improved tumor regression in groups treated with targeted nanoconstructs complexed with MCL-1 siRNA (T + siMCL-1) compared to the other treatment groups. The quantitative RT-PCR results of tumor tissues demonstrated significant MCL-1 gene silencing, i.e., 73.76 % and 92.63 % in breast and prostate tumors, respectively, after T + siMCL-1 treatment. Reduction in MCL-1 protein expression as assessed by immunohistochemistry further confirmed these results. Furthermore, the caspase 3/7 assay demonstrated apoptosis in the MCL-1 silenced tissues. The study strongly suggests that targeted delivery of siRNAs using multi-layered dendrimer nanostructures could be an effective therapy for LHRH overexpressing cancers.

GLUT1 transporter-facilitated solid lipid nanoparticles loaded with anti-cancer therapeutics for ovarian cancer targeting.

The therapeutics available for cancer treatment have the major hurdle of site-specific delivery of anti-cancer drugs to the tumor site and non-target specific side effects. The standard therapy for ovarian cancer still poses numerous pitfalls due to the irrational use of drugs affecting healthy cells. As an appealing approach, nanomedicine could revamp the therapeutic profile of anti-cancer agents. Owing to the low manufacturing cost, increased biocompatibility, and modifiable surface properties, lipid-based nanocarriers, particularly solid lipid nanoparticles (SLN), have remarkable drug delivery properties in cancer treatment. Given the extra-ordinary benefits, we developed anti-neoplastic (paclitaxel) drug-loaded SLN (PTX-SLN) and functionalized with N-acetyl-d-glucosamine (GLcNAc) (GLcNAc-PTX-SLN) to reduce the rate of proliferation, growth, and metastasis of ovarian cancer cells over-expressing GLUT1 transporters. The particles presented considerable size and distribution while demonstrating haemocompatibility. Using GLcNAc modified form of SLNs, confocal microscopy, MTT assay, and flow cytometry study demonstrated higher cellular uptake and significant cytotoxic effect. Also, molecular docking results established excellent binding affinity between GLcNAc and GLUT1, complimenting the feasibility of the therapeutic approach in targeted cancer therapy. Following the compendium of target-specific drug delivery by SLN, our results demonstrated a significant response for ovarian cancer therapy.

Stimuli-responsive mesoporous silica nanoparticles: A custom-tailored next generation approach in cargo delivery.

The pre-mature release of therapeutic cargos in the bloodstream or off-target sites is a major hurdle in drug delivery. However, stimuli-specific drug release responses are capable of providing greater control over the cargo release. Herein, various types of nanocarriers have been employed for such applications. Among various types of nanoparticles, mesoporous silica nanoparticles (MSNPs) have several attractive characteristics, such as high loading capacity, biocompatibility, small size, porous structure, high surface area, tunable pore size and ease of functionalization of the external and internal surfaces, which facilitates the entrapment and development of stimuli-dependent release of drugs. MSNPs could be modified with such stimuli-responsive entities like nucleic acid, peptides, polymers, organic molecules, etc., to prevent pre-mature cargo release, improving the therapeutic outcome. This controlled drug release system could be modulated to function upon extracellular or intracellular specific stimuli, including pH, enzyme, glucose, glutathione, light, temperature, etc., and thus provide minimal side effects at non-target sites. This system has great potential applications for the targeted delivery of therapeutics to treat clinically challenging diseases like cancer. This review summarizes the synthesis and design of stimuli-responsive release strategies of MSNP-based drug delivery systems along with investigations in biomedical applications.

Chemosensitivity assessments of curdlan-doped smart nanocomposites containing erlotinib HCl.

Curdlan (CN)-doped montmorillonite/poly(N-isopropylacrylamide-co-N,N'-methylene-bis-acrylamide) [CN/MT/P(NIPA-co-MBA)] smart nanocomposites (NCs) were developed for efficient erlotinib HCl (ERL) delivery to lung cancer cells. The placebo NCs demonstrated excellent biodegradability, pH/thermo-responsive swelling profiles and declined molar mass (M¯c) between the crosslinks with increasing temperature. The XRD, FTIR, DSC, TGA, and SEM analyses revealed the architectural chemistry of these NC scaffolds. The NCs loaded with ERL (F-1-F-3) displayed acceptable diameter (734-1120 nm) and zeta potential (+1.16 to -11.17 mV), outstanding drug entrapping capability (DEE, 78-99%) and sustained biphasic ERL elution patterns (Q8h, 53-91%). The ERL release kinetics of the optimal matrices (F-3) obeyed Higuchi model and their transport occurred through anomalous diffusion. The mucin adsorption behaviour of these matrices followed Freudlich isotherms. As compared to pure ERL, the formulation (F-3) displayed an improved anti-proliferative potential and induced apoptosis more effectively on A549 cells. Thus, the CN-doped smart NCs could be utilized as promising drug-cargoes for lung cancer therapy.

Efficient in vitro and in vivo docetaxel delivery mediated by pH-sensitive LPHNPs for effective breast cancer therapy.

The present study was designed to develop pH-sensitive lipid polymer hybrid nanoparticles (pHS-LPHNPs) for specific cytosolic-delivery of docetaxel (DTX). The pHS-LPHNPs-DTX formulation was prepared by self-assembled nano-precipitation technique and characterized for zeta potential, particle size, entrapment efficiency, polydispersity index (PDI), and in vitro drug release. In vitro cytotoxicity of pHS-LPHNPs-DTX was assessed on breast cancer cells (MDA-MB-231 and MCF-7) and compared with DTX-loaded conventional LPHNPs and bare DTX. In vitro cellular uptake in MDA-MB-231 cell lines showed better uptake of pHS-LPHNPs. Further, a significant reduction in the IC50 of pHS-LPHNPs-DTX against both breast cancer cells was observed. Flow cytometry results showed greater apoptosis in case of pHS-LPHNPs-DTX treated MDA-MB-231 cells. Breast cancer was experimentally induced in BALB/c female mice, and the in vivo efficacy of the developed pHS-LPHNPs formulation was assessed with respect to the pharmacokinetics, biodistribution in the vital organs (liver, kidney, heart, lungs, and spleen), percentage tumor burden, and survival of breast cancer-bearing animals. In vivo studies showed improved pharmacokinetic and target-specificity with minimum DTX circulation in the deep-seated organs in the case of pHS-LPHNPs-DTX compared to the LPHNPs-DTX and free DTX. Mice treated with pHS-LPHNPs-DTX exhibited a significantly lesser tumor burden than other treatment groups. Also, reduced distribution of DTX in the serum was evident for pHS-LPHNPs-DTX treated mice compared to the LPHNPs-DTX and free DTX. In essence, pHS-LPHNPs mediated delivery of DTX presents a viable platform for developing therapeutic-interventions against breast-cancer.