Solid lipid nanoparticle formulations of docetaxel prepared with high melting point triglycerides: in vitro and in vivo evaluation

Effects of chain length and saturation of triacylglycerols on the characteristics and gastrointestinal digestion fates of curcumin-loaded triacylglycerol nanoparticles

This study assessed the effects of fatty acid length and saturation on the physicochemical, thermal, and gastrointestinal digestive characteristics of curcumin-loaded homo-triacylglycerol nanoparticles (C-NPs). All C-NPs had good colloidal stability and efficiently entrapped curcumin, regardless of their length and saturation. Tricaprylin NPs, with shorter chains, had a smaller size and emulsifier surface load. Curcumin was released faster from low-melting C-NPs (tricaprylin and triolein) than those with high-melting-point (trimyristin, tripalmitin, and tristearin); however, both were negligible without lipolysis. None of the C-NPs underwent significant aggregation, coalescence, or breakdown during digestion before the small intestine. Notably, longer and more saturated chains resulted in a slower initial rate and lower degree of lipolysis in the small intestine. However, greater bioaccessibility of curcumin was observed only with longer chains (tricaprylin, 70.72%; trimyristin, 78.05%; tripalmitin, 85.09%; tristearin, 89.65%; triolein, 89.71%). These findings could be valuable for the development of rational curcumin formulations for functional foods.

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.

Ciprofloxacin Derivative-Loaded Nanoparticles Synergize with Paclitaxel Against Type II Human Endometrial Cancer

Combinations of chemotherapeutic agents comprise a clinically feasible approach to combat cancers that possess resistance to treatment. Type II endometrial cancer is typically associated with poor outcomes and the emergence of chemoresistance. To overcome this challenge, a combination therapy is developed comprising a novel ciprofloxacin derivative-loaded PEGylated polymeric nanoparticles (CIP2b-NPs) and paclitaxel (PTX) against human type-II endometrial cancer (Hec50co with loss of function p53). Cytotoxicity studies reveal strong synergy between CIP2b and PTX against Hec50co, and this is associated with a significant reduction in the IC50 of PTX and increased G2/M arrest. Upon formulation of CIP2b into PEGylated polymeric nanoparticles, tumor accumulation of CIP2b is significantly improved compared to its soluble counterpart; thus, enhancing the overall antitumor activity of CIP2b when co-administered with PTX. In addition, the co-delivery of CIP2b-NPs with paclitaxel results in a significant reduction in tumor progression. Histological examination of vital organs and blood chemistry was normal, confirming the absence of any apparent off-target toxicity. Thus, in a mouse model of human endometrial cancer, the combination of CIP2b-NPs and PTX exhibits superior therapeutic activity in targeting human type-II endometrial cancer.

Solid Lipid Nanoparticles for Pulmonary Delivery of Biopharmaceuticals: A Review of Opportunities, Challenges, and Delivery Applications

Biopharmaceuticals such as nucleic acids, proteins, and peptides constitute a new array of treatment modalities for chronic ailments. Invasive routes remain the mainstay of administering biopharmaceuticals due to their labile nature in the biological environment. However, it is not preferred for long-term therapy due to the lack of patient adherence and clinical suitability. Therefore, alternative routes of administration are sought to utilize novel biopharmaceutical therapies to their utmost potential. Nanoparticle-mediated pulmonary delivery of biologics can facilitate both local and systemic disorders. Solid lipid nanoparticles (SLNs) afford many opportunities as pulmonary carriers due to their physicochemical stability and ability to incorporate both hydrophilic and hydrophobic moieties, thus allowing novel combinatorial drug/gene therapies. These applications include pulmonary infections, lung cancer, and cystic fibrosis, while systemic delivery of biomolecules, like insulin, is also attractive for the treatment of chronic ailments. This Review explores physiological and particle-associated factors affecting pulmonary delivery of biopharmaceuticals. It compares the advantages and limitations of SLNs as pulmonary nanocarriers along with design improvements underway to overcome these limitations. Current research illustrating various SLN designs to deliver proteins, peptides, plasmids, oligonucleotides, siRNA, and mRNA is also summarized.

Co-Delivery of siRNA and Docetaxel to Cancer Cells by NLC for Therapy

The present study aims to develop a delivery system that can carry small interference RNA (siRNA) with small-molecule chemotherapeutic drugs, which can be used in cancer treatment. The drug delivery system combines the advantages of a therapeutic agent with two different mechanisms to ensure that it is used efficiently for cancer therapy. In this study, a nanostructured lipid carrier system was prepared, Docetaxel was loaded to these systems, and the Eph siRNA was adsorbed to the outer surface. In addition, DOTAP was added to the lipophilic phase to load a positive charge on the lipidic structure for interaction with the cells. Moreover, characterization, cytotoxicity, and transfection procedures were performed on the whole system. This candidate system was also compared to Taxotere, which is the first approved Docetaxel-containing drug on the market. Given the results, it was determined that the particle size of NLC-DTX was 165.3 ± 3.5 nm, the ζ potential value was 38.2 ± 1.7 mV, and the PDI was 0.187 ± 0.024. Entrapment efficacy of nanoparticles was found to be 92.89 ± 0.21%. It was determined that the lipidic system prepared in vitro release analyses were able to provide sustained release and exhibit cytotoxicity, even at doses lower than the dose used for Taxotere. The formulations prepared had a higher level of effect on cells when compared with pure DTX and Taxotere, but they also exhibited time-dependent cytotoxicity. It was also observed that the use of Eph siRNA together with the chemotherapeutic agent via formulation also contributed to this cell death. The results of the present study indicate that there is a promising carrier system in order to deliver hydrophilic nucleic acids, such as siRNA, together with lipophilic drugs in cancer treatment.

Adjuvant Novel Nanocarrier-Based Targeted Therapy for Lung Cancer

Lung cancer has the lowest survival rate due to its late-stage diagnosis, poor prognosis, and intra-tumoral heterogeneity. These factors decrease the effectiveness of treatment. They release chemokines and cytokines from the tumor microenvironment (TME). To improve the effectiveness of treatment, researchers emphasize personalized adjuvant therapies along with conventional ones. Targeted chemotherapeutic drug delivery systems and specific pathway-blocking agents using nanocarriers are a few of them. This study explored the nanocarrier roles and strategies to improve the treatment profile's effectiveness by striving for TME. A biofunctionalized nanocarrier stimulates biosystem interaction, cellular uptake, immune system escape, and vascular changes for penetration into the TME. Inorganic metal compounds scavenge reactive oxygen species (ROS) through their photothermal effect. Stroma, hypoxia, pH, and immunity-modulating agents conjugated or modified nanocarriers co-administered with pathway-blocking or condition-modulating agents can regulate extracellular matrix (ECM), Cancer-associated fibroblasts (CAF),Tyro3, Axl, and Mertk receptors (TAM) regulation, regulatory T-cell (Treg) inhibition, and myeloid-derived suppressor cells (MDSC) inhibition. Again, biomimetic conjugation or the surface modification of nanocarriers using ligands can enhance active targeting efficacy by bypassing the TME. A carrier system with biofunctionalized inorganic metal compounds and organic compound complex-loaded drugs is convenient for NSCLC-targeted therapy.

Several Applications of Solid Lipid Nanoparticles in Drug Delivery

Rapid progress is being made in the area of nanotechnology; solid lipid nanoparticles are currently at the forefront of research and development. They have the capability of becoming employed in an extensive number of applications, including the delivery of medications, clinical treatment, and research, in addition to uses in other areas of academic inquiry that could benefit from their utilisation. This article presents a thorough analysis of solid lipid nanoparticles, covering subjects such as their goals, preparation strategy, applications, advantages, and possible remedies for the issues that have been raised. This review provides a discussion of solid lipids that is both in-depth and comprehensive. Studies that investigate the manner in which SLNs are prepared and the routes via which they are administered are typical. Aspects concerning the route of administration of SLNs as well as the destiny of the carriers in vivo are also investigated in this paper.

Cubic nanoparticles as potential carriers for a natural anticancer drug: development, in vitro and in vivo characterization

Natural compounds that elicit anticancer properties are of great interest for cancer therapy. However, the low solubility and bioavailability of these compounds limit their use as efficient anticancer drugs. To avoid these drawbacks, incorporation of these compounds into cubic nanoparticles (cubosomes) was carried out. Cubosomes containing bergapten which is a natural anticancer compound isolated from Ficus carica were prepared by the homogenization technique using monoolein and poloxamer. These cubosomes were characterized for size, zeta potential, entrapment efficiency, small angle X-ray diffraction, in vitro release, in vitro cytotoxicity, cellular uptake, and antitumor activity. Particle size of cubosomes was 220 ± 3.6 nm with almost neutral zeta potential - 5 ± 1.2 mV and X-ray measurements confirmed the existence of the cubic structure. Additionally, more than 90% of the natural anticancer drug was entrapped within the cubosomes. A sustained release over 30 h was obtained for these cubosomes. Finally, these cubosomes illustrated higher in vitro cytotoxicity and in vivo tumor inhibition compared with the free natural anticancer compound. Thus, cubosomes could be promising carriers for enhancement of antitumor efficiency of this natural compound.

Novel Meta-iodobenzylguanidine and Etoposide Complex: Physicochemical Characterization and Mathematical Modeling of Anticancer Activity

It is hypothesized that meta-iodobenzylguanidine (MIBG) complexation with etoposide (VP-16) will improve drug solubility and specificity towards BE(2)C neuroblastoma (NB) cells, 90% of which are known to be MIBG avid. After MIBG and VP-16 interaction, the dry complex was analyzed for crystalline structure, surface morphology, solubility, and size distribution by X-ray powder diffraction (P-XRD), scanning electron microscopy (SEM), infrared (FTIR) and UV spectroscopy, and dynamic light scattering. After exposure to the complex, the cell viability and decay rates were assessed by the MTS assay and estimated using exponential decay models (EDM). Multi-factorial ANOVA and an independent t-test were used to assess for cell viability and solubility data, respectively. The resulting (1: 3 w/w) VP-16: MIBG complex had a mean diameter and zeta potential of 458.5 nm and 0.951 mV, respectively. It dramatically increased the drug apparent water solubility (~ 12-folds). This was ascribed to the formation of a VP-16/MIBG nanocrystalline state mainly governed by cation-π interactions, evidenced by FTIR, SEM, and P-XRD data following the complexation. The EDM relating percent cell viability to drug concentration yielded an excellent fit (r2 > 0.95) and enabled to estimate the IC50 values of both native drug and its complex: 6.2 μM and 5.23 μM, respectively (indicating a conservation of drug anticancer activity). The statistical results were consistent with those of the exponential decay models, indicating that MIBG does not inhibit the anticancer activity of VP-16. This study indicates that the VP-16/MIBG complexation improves VP-16 solubility without antagonizing its anticancer activity. Moreover, the efficiency of the EDM for drug IC50 estimation provides alternative mathematical method for such in vitro cytotoxicity studies.

Chitosan-Coated SLN: A Potential System for Ocular Delivery of Metronidazole

Ophthalmic drops for ocular delivery exhibit inadequate residence time, which often requires multiple daily dosing that may result in patient non-adherence. In this study, the development of a once-daily-dosed chitosan-coated metronidazole (MTZ)-loaded solid lipid nanoparticles (SLNs) for ocular delivery was undertaken. Melt emulsification and ultrasonication were used to manufacture MTZ-loaded SLN, which were subsequently coated with chitosan (CS) by mechanical stirring using a 0.1% w/v solution. Gelucire^® 48/16 and Transcutol^® HP were used as the solid lipid and synthetic solvent, respectively, with Tween^® 20 included as a stabilizing agent. The critical quality attributes (CQA) of the optimized CS-coated SLN that was monitored included particle size, polydispersity index, Zeta potential, % entrapment efficiency, % MTZ loading, pH, and osmolarity. The optimized coated nanocarriers were evaluated using laser Doppler anemometry (LDA) and were determined to be stable, with particle sizes in the nanometre range. In vitro mucoadhesion, MTZ release and short-term stability, in addition to the determination of the shape of the optimized CS-coated SLN, were undertaken. The mucoadhesive properties of the optimized CS-coated MTZ-loaded SLN demonstrated increased ocular availability, which may allow dose reduction or longer intervals between doses by improving precorneal retention and ocular availability. Overall, our findings suggest that CS-coated MTZ-loaded SLNs have the potential for clinical application, to enhance ocular delivery through the release of MTZ.

Design, development, and in-vitro/in-vivo evaluation of Docetaxel-loaded PEGylated Solid Lipid Nanoparticles in Prostate Cancer Therapy

Docetaxel (DOC) is a potent anticancer molecule widely used to treat various cancers. However, its therapeutic efficacy as a potential anticancer agent has been limited owing to poor aqueous solubility, short circulation time, rapid reticuloendothelial system uptake, and high renal clearance, which consecutively showed poor bioavailability. In the present investigation, we developed polyethylene glycol (PEG) decorated solid lipid nanoparticles (SLN) using the solvent diffusion method to increase the biopharmaceutical properties of DOC. PEG monostearate (SA-PEG₂₀₀₀) was initially synthesized and characterized using various analytical techniques. Afterwards, DOC-loaded SLN was synthesized with and without SA-PEG₂₀₀₀and systematically characterized for in-vitro and in-vivo properties. Spherical-shaped SA-PEG₂₀₀₀-DOC SLN showed hydrodynamic diameter and zeta potential of 177 nm and -13 mV, respectively. During the in-vitro release study DOC-loaded SLN showed a controlledrelease of approximately 54.35 % ±5.46 within 12 h with Higuchi release kinetics in the tumor microenvironment (pH 5.5).In an in-vitro cytotoxicity study,SA-PEG₂₀₀₀-DOC SLN showedsignificantlylower IC₅₀values(p < 0.001)compared to DOC-SLN and DOC aloneagainst prostate cancer cell lines (PC-3). Similarly, an in-vitro cellular uptake study showed a significant increase in intracellular DOC concentration for SA-PEG₂₀₀₀-DOC SLN. Additionally, inin-vivostudies,PEGylated SLN of DOC showed around 2- and 15-fold increase in the maximum concentration of drug (Cmax) and area under the curve (AUC), respectively, as compared to plain DOC solution due to the uniquehydrophilicity and hydrophobicity balance and electrical neutrality of specially designed PEG architect. The biological half-life (t_1/2) and mean residence time (MRT) was found to increase from 8.55 and 11.43 to 34.96 and 47.68 h, respectively, with SA-PEG₂₀₀₀-DOC SLN. Moreover, the bio-distribution study indicates high DOC concentration in the plasma which signifies the more pronounced blood residence time of SA-PEG₂₀₀₀-DOC SLN. In a nutshell, SA-PEG₂₀₀₀-DOC SLNwasfound to bea promising and efficient drug delivery platform for the management of Metastatic Prostate cancer.

Nanostructured Lipid Carrier Co-Loaded with Docetaxel and Magnetic Nanoparticles: Physicochemical Characterization and In Vitro Evaluation

Lung cancer is currently the most prevalent cause of cancer mortality due to late diagnosis and lack of curative therapies. Docetaxel (Dtx) is clinically proven as effective, but poor aqueous solubility and non-selective cytotoxicity limit its therapeutic efficacy. In this work, a nanostructured lipid carrier (NLC) loaded with iron oxide nanoparticles (IONP) and Dtx (Dtx-MNLC) was developed as a potential theranostic agent for lung cancer treatment. The amount of IONP and Dtx loaded into the Dtx-MNLC was quantified using Inductively Coupled Plasma Optical Emission Spectroscopy and high-performance liquid chromatography. Dtx-MNLC was then subjected to an assessment of physicochemical characteristics, in vitro drug release, and cytotoxicity. Dtx loading percentage was determined at 3.98% w/w, and 0.36 mg/mL IONP was loaded into the Dtx-MNLC. The formulation showed a biphasic drug release in a simulated cancer cell microenvironment, where 40% of Dtx was released for the first 6 h, and 80% cumulative release was achieved after 48 h. Dtx-MNLC exhibited higher cytotoxicity to A549 cells than MRC5 in a dose-dependent manner. Furthermore, the toxicity of Dtx-MNLC to MRC5 was lower than the commercial formulation. In conclusion, Dtx-MNLC shows the efficacy to inhibit lung cancer cell growth, yet it reduced toxicity on healthy lung cells and is potentially capable as a theranostic agent for lung cancer treatment.

Comparative study on the performance of monoolein cubic nanoparticles and trimyristin solid lipid nanoparticles as carriers for docetaxel

Nowadays the application of lipid nanoparticles as carriers for the delivery of anticancer drugs gained great attention in cancer therapy. Solid lipid nanoparticles (SLN_s) and cubic nanoparticles (cubosomes) are considered as promising carriers in cancer therapy. The comparison of these two lipid nanoparticles as efficient carriers for the anticancer drug docetaxel was our main goal in this study. Both nanoparticles were prepared by the hot melt homogenization technique followed by measurement of particle size, zeta potential, entrapment efficiency and in vitro release of docetaxel. An advanced technique has been applied to measure the release of docetaxel from these nanoparticles using small unilamellar vesicles (SUV_s) as acceptor particles which resemble many compartments in our body. All prepared nanoparticles revealed a neutral zeta potential with particle sizes of about 200 nm. While SUV_s showed a negative surface charge with a zeta potential of -55 mV, cubosomes showed higher entrapment efficiency and a slower docetaxel release compared to SLN_s. Additionally, cubosomes improved in vitro cytotoxicity as well as the in vivo antitumor inhibition of docetaxel compared to SLN_s and docetaxel solution. Overall, our results showed that incorporation of docetaxel into cubosomes could enhance its in vitro and in vivo performance compared to docetaxel incorporated into SLN_s.

A comparative study on micelles, liposomes and solid lipid nanoparticles for paclitaxel delivery

The purpose of this work was to compare the in vitro and in vivo characteristics of LDV-targeted lipid-based micelles, liposomes and solid lipid nanoparticles (SLN) to provide further insights into their therapeutic potential for clinical development. Micelles, liposomes and SLN were prepared using LDV peptide amphiphiles and palmitic acid-derived lipids using solvent evaporation, thin-film hydration and microfluidic mixing respectively. Nanocarriers were characterized for their physicochemical properties, paclitaxel loading efficiency, in vitro release behavior, stability in biological media as well as in vivo antitumor efficacy in melanoma xenograft model. TEM and DLS results confirmed the presence of paclitaxel-loaded nanosized micelles (6 to 12 nm), liposomes (123.31 ± 5.87 nm) and SLN (80.53 ± 5.37 nm). SLN demonstrated the slowest paclitaxel release rate and the highest stability in biological media compared to micelles and liposomes. Paclitaxel-loaded SLN demonstrated a statistically significant delay in tumor growth compared to mice treated with paclitaxel-loaded liposomes and paclitaxel-loaded micelles (p < 0.05). The results obtained in this study indicate the potential of SLN as drug delivery vehicles for anticancer therapy.

Advances in Lung Cancer Treatment Using Nanomedicines

Carcinoma of the lungs is among the most menacing forms of malignancy and has a poor prognosis, with a low overall survival rate due to delayed detection and ineffectiveness of conventional therapy. Therefore, drug delivery strategies that may overcome undesired damage to healthy cells, boost therapeutic efficacy, and act as imaging tools are currently gaining much attention. Advances in material science have resulted in unique nanoscale-based theranostic agents, which provide renewed hope for patients suffering from lung cancer. Nanotechnology has vastly modified and upgraded the existing techniques, focusing primarily on increasing bioavailability and stability of anti-cancer drugs. Nanocarrier-based imaging systems as theranostic tools in the treatment of lung carcinoma have proven to possess considerable benefits, such as early detection and targeted therapeutic delivery for effectively treating lung cancer. Several variants of nano-drug delivery agents have been successfully studied for therapeutic applications, such as liposomes, dendrimers, polymeric nanoparticles, nanoemulsions, carbon nanotubes, gold nanoparticles, magnetic nanoparticles, solid lipid nanoparticles, hydrogels, and micelles. In this Review, we present a comprehensive outline on the various types of overexpressed receptors in lung cancer, as well as the various targeting approaches of nanoparticles.

Docetaxel Loaded in Copaiba Oil-Nanostructured Lipid Carriers as a Promising DDS for Breast Cancer Treatment

Breast cancer is the neoplasia of highest incidence in women worldwide. Docetaxel (DTX), a taxoid used to treat breast cancer, is a BCS-class-IV compound (low oral bioavailability, solubility and intestinal permeability). Nanotechnological strategies can improve chemotherapy effectiveness by promoting sustained release and reducing systemic toxicity. Nanostructured lipid carriers (NLC) encapsulate hydrophobic drugs in their blend-of-lipids matrix, and imperfections prevent drug expulsion during storage. This work describes the preparation, by design of experiments (2³ factorial design) of a novel NLC formulation containing copaiba oil (CO) as a functional excipient. The optimized formulation (NLC_DTX) showed approximately 100% DTX encapsulation efficiency and was characterized by different techniques (DLS, NTA, TEM/FE-SEM, DSC and XRD) and was stable for 12 months of storage, at 25 °C. Incorporation into the NLC prolonged drug release for 54 h, compared to commercial DTX (10 h). In vitro cytotoxicity tests revealed the antiproliferative effect of CO and NLC_DTX, by reducing the cell viability of breast cancer (4T1/MCF-7) and healthy (NIH-3T3) cells more than commercial DTX. NLC_DTX thus emerges as a promising drug delivery system of remarkable anticancer effect, (strengthened by CO) and sustained release that, in clinics, may decrease systemic toxicity at lower DTX doses.

Approaches for designing and delivering solid lipid nanoparticles of distinct antitubercular drugs

Tuberculosis (TB) is still the biggest infectious disease among adults globally, which effects the social and biological lives of patients as well as the economic liability of healthcare systems. Current treatment regime has challenges with drug resistant (MDR/XDR) strains and the failure of standard therapeutic interventions against these TB strains. In the recent years, several nanocarrier-based drug delivery systems developed (including lipid-based) with anti-tuberculosis drugs via targeted delivery to improve the therapeutic outcomes. In this review, we attempt to summarize on the composition of the reported solid lipid-based particles (SLNPs), their various production methodologies, and properties of the delivery system, and their influence on cellular and pharmacokinetic aspects are also discussed. Besides, we have highlighted anti-TB drugs delivering via lipid-based systems have shown promising outcomes, however clinical translation of such systems is still under investigation. Based on recent advancements and reports, it is recommended that future efforts be made to accelerate the translational development of lipid-based nanocarriers to improve TB treatment.

Cisplatin-Loaded Tobacco Mosaic Virus for Ovarian Cancer Treatment

Ovarian cancer is the foremost cause of gynecological cancer and a major cause of cancer death in women. Treatment for advanced stage is surgical debulking followed by chemotherapy; however, most patients relapse with more aggressive and therapy-resistant tumors. There is a need to develop drug delivery approaches to deliver platinum therapies to tumors to increase efficacy while maintaining safety. Toward this goal, we utilized the protein nanotubes from the plant virus, tobacco mosaic virus (TMV), as a drug carrier. Specifically, the nanochannel of TMV was loaded with the active dication form of cisplatin (cisPt²⁺), making use of the negatively charged Glu acid side chains that line the interior channel of TMV. We achieved a loading efficiency with ∼2700 cisPt²⁺ per TMV; formulation stability was established with drug complexes stably loaded into the carrier for 2 months under refrigerated storage. TMV-cisPt maintained its efficacy against ovarian tumor cells with an IC₅₀ of ∼40 μM. TMV-cisPt exhibited superior efficacy vs free cisPt in ovarian tumor mouse models using intraperitoneal ID8-Defb29/Vegf-a-Luc (mouse) tumors and subcutaneous A2780 (human) xenografts. TMV-cisPt treatment led to reduced tumor burden and increased survival. Using ID8-Defb29/Vegf-a-Luc-bearing C57BL/6 mice, we also noted reduced tumor growth when animals were treated with TMV alone, which may indicate antitumor immunity induced by the immunomodulatory nature of the plant virus nanoparticle. Biodistribution studies supported the efficacy data, showing increased cisPt accumulation within tumors when delivered via the TMV carrier vs free cisPt administration. Finally, good safety profiles were noted. The study highlights the potential of TMV as a drug carrier against cancer and points to the opportunity to explore plant viruses as chemo-immuno combination cancer therapeutics.

Biopolymeric Prodrug Systems as Potential Antineoplastic Therapy

Nowadays, cancer represents a major public health issue, a substantial economic issue, and a burden for society. Limited by numerous disadvantages, conventional chemotherapy is being replaced by new strategies targeting tumor cells. In this context, therapies based on biopolymer prodrug systems represent a promising alternative for improving the pharmacokinetic and pharmacologic properties of drugs and reducing their toxicity. The polymer-directed enzyme prodrug therapy is based on tumor cell targeting and release of the drug using polymer–drug and polymer–enzyme conjugates. In addition, current trends are oriented towards natural sources. They are biocompatible, biodegradable, and represent a valuable and renewable source. Therefore, numerous antitumor molecules have been conjugated with natural polymers. The present manuscript highlights the latest research focused on polymer–drug conjugates containing natural polymers such as chitosan, hyaluronic acid, dextran, pullulan, silk fibroin, heparin, and polysaccharides from Auricularia auricula.

PEGylated solid lipid nanoparticles functionalized by aptamer for targeted delivery of docetaxel in mice bearing C26 tumor

OBJECTIVE

Colorectal cancer is one of the most deadly cancers in the world. Docetaxel (DTX) is a potentially important chemotherapeutic agent for the treatment of cancer. Many studies have attempted to improve its bioavailability and efficiency using different nanoparticulate drug delivery systems.

SIGNIFICANCE

In the current study, PEGylated solid lipid nanoparticles (SLNs) containing DTX were prepared and modified with AS1411 anti-nucleolin aptamers to target nucleoin receptors on colorectal cancer cells.

METHODS

Nanoparticles were characterized and the morphology was evaluated. In vitro studies were investigated on murine colon carcinoma (C26) and Chinese hamster ovary (CHO) cell lines. Then in vivo antitumor efficacy and survival analysis were evaluated in mice bearing the C26 tumor model.

RESULTS

Results showed 135-140 nm particle size and about 78% DTX entrapment efficiency for actively targeted samples. PEGylated and aptamer-targeted SLNs containing DTX had the lowest IC₅₀ (0.28 and 0.11 nM for 3 and 6 h incubation respectively) and higher cellular uptake values in the C26 cell line. Also in vivo results demonstrated that PEGylated and aptamer-targeted SLNs containing Docetaxel (Apt-PEG-SLN-DTX) improved antitumor activity and inhibited tumor growth in C26 tumor-bearing mice.

CONCLUSION

These results suggested that PEGylated and aptamer-targeted SLNs containing DTX exhibited efficient characteristics in tumor inhibitory against murine C26 carcinoma model.

Self-Assembled Nanomicellar Formulation of Docetaxel as a Potential Breast Cancer Chemotherapeutic System

Docetaxel (DTX) is classified as a class IV drug that exhibits poor aqueous solubility (6–7 µg/mL in water) and permeability (P-glycoprotein substrate). The main objective of this study was to construct, characterize, and evaluate docetaxel loaded nanomicellar formulation in vitro for oral delivery to enhance the absorption and bioavailability of DTX, as well as to circumvent P-gp efflux inhibition. Formulations were prepared with two polymeric surfactants, hydrogenated castor oil-40 (HCO-40) and D-α-Tocopherol polyethylene glycol 1000 succinate (VIT E TPGS) with solvent evaporation technique, and the resulting DTX nanomicellar formulations were characterized by proton nuclear magnetic resonance spectroscopy (1H NMR), Fourier Transform Infrared Spectroscopy (FT–IR), X-ray powder diffraction (XRD), and transmission electron microscopy (TEM). Proton NMR, FT–IR, and XRD data indicated that DTX was completely encapsulated within the hydrophobic core of the nanomicelles in its amorphous state. TEM data revealed a smooth spherical shape of the nanomicellar formulation. The optimized formulation (F-2) possessed a mean diameter of 13.42 nm, a zeta potential of −0.19 mV, with a 99.3% entrapment efficiency. Dilution stability study indicated that nanomicelles were stable up to 100-fold dilution with minimal change in size, poly dispersity index (PDI), and zeta potential. In vitro cytotoxicity study revealed higher anticancer activity of DTX nanomicelles at 5 µM compared to the native drug against breast cancer cell line (MCF-7) cells. The LC–MS data confirmed the chemical stability of DTX within the nanomicelles. In vitro drug release study demonstrated faster dissolution of DTX from the nanomicelles compared to the naked drug. Our experimental results exhibit that nanomicelles could be a drug delivery system of choice to encapsulate drugs with low aqueous solubility and permeability that can preserve the stability of the active constituents to provide anticancer activity.

Ion exchange column technique as a novel method for evaluating the release of docetaxel from different lipid nanoparticles

Lipid nanoparticles with their unique characters showed many advantages as carriers for anticancer drugs. To compare between these nanoparticles as carriers for anticancer drugs, it was important to evaluate and characterize their drug retention and release properties. In this study, ion exchange column is used as a new evaluation technique. Solid lipid nanoparticles (SLN), nanostructured lipid carrier (NLC), and cubic nanoparticles were prepared using the homogenization technique. Characterization of these nanoparticles was carried out by measuring particle size, zeta potential, and entrapment efficiency. The ion exchange column was used to evaluate docetaxel release from the different nanoparticles as donors to acceptor liposomes that mimic the cell membranes. Both populations were mixed and at different time points, separated using the columns. The amounts of docetaxel in the eluted nanoparticles and retained liposomes were calculated. The particle size of all donors was in the nanometer range with almost neutral zeta potential. The particle size of the acceptor liposomes was 135 nm with a high negative zeta potential -55 mV. Ion exchange columns showed excellent retention of the negative acceptor liposomes while less than 1% of the different donors were retained on the columns. Cubic nanoparticles showed the highest entrapment efficiency (95%) and the slowest drug transfer in comparison with SLN and NLC. In conclusion, the ion exchange column technique can be applied successfully to evaluate the release of docetaxel from the different lipid nanoparticles to acceptor liposomes. Cubic nanoparticles showed advantageous docetaxel incorporation and transfer over SLN and NLC.

Self-Assembled Nanomicelles to Enhance Solubility and Anticancer Activity of Etoposide

It is hypothesized that etoposide/VP-16 nanomicellar formulation (VP-16 NMF) utilizing D-α-Tocopherol polyethylene glycol 1000 succinate (TPGS) can improve etoposide solubility and anticancer activity. The following four different concentrations of TPGS: 3, 6, 8, and 10 wt% were used to solubilize the drug. Among these four formulations, 10 wt% of TPGS loaded with VP-16 NMF dramatically enhanced etoposide apparent solubility by 26-folds compared with the native drug. The physicochemical properties of the optimized formulation were further analyzed by dynamic light scattering, X-ray powder diffraction, scanning electron microscopy, proton nuclear magnetic resonance (¹HNMR) and Fourier transform infrared spectroscopy. Liquid chromatography tandem-mass spectrometry (LC-MS/MS) was used to assess solubility and intracellular uptake of the drug from the NMF. Cell viability assay ([3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H tetrazolium solution [MTS]) was performed on MCF-7 and MCF-10A cell lines to assess intracellular uptake and anticancer activity of etoposide. The MTS assay results showed that the VP-16 NMF platform provides a higher anticancer activity than the native VP-16 on the MCF-7 cells line as it integrates a dual anticancer activity of VP-16 and TPGS. LC-MS/MS data showed a threefold increase in cellular uptake of VP-16 NMF in MCF-7 cell line compared with the native etoposide. These data suggest that an optimal TPGS concentration can improve VP-16 bioavailability and efficacy with potential benefits for chemotherapy.

Enhancing Etoposide Aqueous Solubility and Anticancer Activity with L-Arginine

It is hypothesized that L-arginine (ARG) can improve etoposide (VP-16) water solubility while preserving its anticancer activity. Factorial design is used to identify conditions for optimum drug aqueous solubility after freeze-drying. The physicochemical properties of the optimized formulation is further analyzed by X-ray powder diffraction, scanning electron microscopy, proton nuclear magnetic resonance, and fourier transform infrared spectroscopy. Drug stability in formulation is analyzed using mass spectrometry based fragmentation analysis. Liquid chromatography tandem mass spectrometry and cell viability assay on Michigan Cancer Foundation-7 (MCF-7) cell line are performed to assess the drug cellular uptake and the anticancer activity, respectively. At the VP-16: ARG ratio of 4:10 (w/w), the drug apparent solubility increased significantly (∼65-folds) with a 3.5-fold improvement in the drug dissolution rate. The interaction between VP-16 and ARG transforms the drug from crystalline to amorphous solid state. VP-16-ARG complex in lower native drug concentration range (50-300 μM) has lower anticancer activity compared with native VP-16, due to reduced intracellular transport of the more hydrophilic complex as indicated by the cell viability assay and confirmed by cell uptake study. However, at higher drug concentrations (500 μM) the complex's higher anticancer activity is ascribed to the synergistic effect between ARG and VP-16. These data suggest that an optimal ARG concentration can have positive effects with potential benefits for chemotherapy.

The MEK 1/2 inhibitor PD98059 exhibits synergistic anti-endometrial cancer activity with paclitaxel in vitro and enhanced tissue distribution in vivo when formulated into PAMAM-coated PLGA-PEG nanoparticles

Endometrial cancer is the most common gynecological cancer that affects the female reproductive organs. The standard therapy for EC for the past two decades has been chemotherapy and/or radiotherapy. PD98059 is a reversible MEK inhibitor that was found in these studies to increase the cytotoxicity of paclitaxel (PTX) against human endometrial cancer cells (Hec50co) in a synergistic and dose-dependent manner. Additionally, while PD98059 arrested Hec50co cells at the G₀/G₁ phase, and PTX increased accumulation of cells at the G₂/M phase, the combination treatment increased accumulation at both the G₀/G₁ and G₂/M phases at low PTX concentrations. We recently developed poly(lactide-co-glycolide) (PLGA) nanoparticles (NPs) modified with polyethylene glycol (PEG) and coated with polyamidoamine (PAMAM) (referred to here as PGM NPs) which have favorable biodistribution profiles in mice, compared to PD98059 solution. Here, in order to enhance tissue distribution of PD98059, PD98059-loaded PGM NPs were prepared and characterized. The average size, zeta potential, and % encapsulation efficiency (%EE) of these NPs was approximately 184 nm, + 18 mV, and 23%, respectively. The PD98059-loaded PGM NPs released ~ 25% of the total load within 3 days in vitro. In vivo murine studies revealed that the pharmacokinetics and biodistribution profile of intravenous (IV) injected PD98059 was improved when delivered as PD98059-loaded PGM NPs as opposed to soluble PD98059. Further investigation of the in vivo efficacy and safety of this formulation is expected to emphasize the potential of its clinical application in combination with commercial PTX formulations against different cancers.

Perfluorocarbons therapeutics in modern cancer nanotechnology for hypoxia-induced anti-tumor therapy

With an estimated failure rate of about 90%, immunotherapies that are intended for the treatment of solid tumors have caused an anomalous rise in the mortality rate over the past decades. It is apparent that resistance towards such therapies primarily occurs due to elevated levels of HIF-1 (Hypoxia-induced factor) in tumor cells, which are caused by disrupted microcirculation and diffusion mechanisms. With the advent of nanotechnology, several innovative advances were brought to the fore; and, one such promising direction is the use of perfluorocarbon nanoparticles in the management of solid tumors. Perfluorocarbon nanoparticles enhance the response of hypoxia-based agents (HBAs) within the tumor cells and have been found to augment the entry of HBAs into the tumor micro-environment. The heightened penetration of HBAs causes chronic hypoxia, thus aiding in the process of cell quiescence. In addition, this technology has also been applied in photodynamic therapy, where oxygen self-enriched photosensitizers loaded perfluorocarbon nanoparticles are employed. The resulting processes initiate a cascade, depleting tumour oxygen and turning it into a reactive oxygen species eventually to destroy the tumour cell. This review elaborates on the multiple applications of nanotechnology based perfluorocarbon formulations that are being currently employed in the treatment of tumour hypoxia.

Recent Advances in Herbal Nanomedicines for Cancer Treatment

Cancer continues to be one of the deadliest diseases that adversely impacts the large population of the world. A stack of scientific documents reflects a huge number of potent plant-based anticancer drugs such as curcumin (CUR), podophyllotoxin, camptothecin (CPT), vincristine, vinblastine, paclitaxel (PTX), etc. that have been integrated into the modern practice of cancer treatment. The demand for natural products raises exponentially as they are generally considered to be safe, and devoid of critical toxic effects at the therapeutic dose when compared to their synthetic counterparts. Despite rising interest towards the potent phytoconstituents, formulation developer faces various challenges in drug development processes such as poor water solubility, low bioavailability, marginal permeability, and nonspecific drug delivery at the target site, etc. Further, adverse drug reaction and multidrug resistance are other critical issues that need to be addressed. Nanomedicines owing to their unique structural and functional attributes help to fix the above challenges for improved translational outcomes. This review summarises the prospects and challenges of a nanotechnology-based drug delivery approach for the delivery of plant-based anticancer drugs.

Paclitaxel anticancer activity is enhanced by the MEK 1/2 inhibitor PD98059 in vitro and by PD98059-loaded nanoparticles in BRAFV600E melanoma-bearing mice

Melanoma, the most malignant form of skin cancer, shows resistance to traditional anticancer drugs including paclitaxel (PTX). Furthermore, over 50% of melanoma cases express the BRAF^V600E mutation which activates the MAPK pathway increasing cell proliferation and survival. In the current study, we investigated the capacity of the combination therapy of PTX and the MAPK inhibitor, PD98059, to enhance the cytotoxicity of PTX against melanoma and therefore improve treatment outcomes. Synergistic in vitro cytotoxicity was observed when soluble PTX and PD98059 were used to treat the A375 melanoma cell line as evidenced by a significant reduction in the cell viability and IC₅₀ value for PTX. Then, in further studies, TPGS-emulsified PD98059-loaded PLGA nanoparticles (NPs) were prepared, characterized in vitro and assessed for therapeutic efficacy when used in combination with soluble PTX. The average particle size (180 nm d.), zeta potential (-34.8 mV), polydispersity index (0.081), encapsulation efficiency (20%), particle yield (90.8%), and drug loading (6.633 µg/mg) of the prepared NPs were evaluated. Also, cellular uptake and in vitro cytotoxicity studies were performed with these PD98059-loaded NPs and compared to soluble PD98059. The PD98059-loaded NPs were superior to soluble PD98059 in terms of both cellular uptake and in vitro cytotoxicity in A375 cells. In in vivo studies, using A375 challenged mice, we report improved survival in mice treated with soluble PTX and PD98059-loaded NPs. Our findings suggest the potential for using this combinatorial therapy in the management of patients with metastatic melanoma harboring the BRAF mutation as a means to improve survival outcomes.

Challenges in Oral Drug Delivery and Applications of Lipid Nanoparticles as Potent Oral Drug Carriers for Managing Cardiovascular Risk Factors

BACKGROUND

The oral application of drugs is the most popular route through which the systemic effect can be achieved. Nevertheless, oral administration is limited by difficulties related to the physicochemical properties of the drug molecule, including low aqueous solubility, instability, low permeability, and rapid metabolism, all of which result in low and irregular oral bioavailability.

OBJECTIVE

The enhancement of oral bioavailability of drug molecules with such properties could lead to extreme complications in drug preparations. Oral lipid-based nanoparticles seem to possess extensive advantages due to their ability to increase the solubility, simplifying intestinal absorption and decrease or eradicate the effect of food on the absorption of low soluble, lipophilic drugs and therefore improving the oral bioavailability.

METHODS

The present review provides a summary of the general theory of lipid-based nanoparticles, their preparation methods, as well as their oral applications. Moreover, oral drug delivery challenges are discussed.

RESULTS

According to this review, the most frequent types of lipid-based nanoparticle, the solid lipid nanoparticles and nanostructured lipid carriers are potent oral carriers due to their ability to penetrate the oral drug adsorption barriers. Moreover, such lipid nanoparticles can be beneficial drug carriers against cardiovascular risk disorders as diabetes, hypertension, etc. Conclusion: In this review, the most current and promising studies involving Solid Lipid Nanoparticles and Nanostructured Lipid Carriers as oral drug carriers are reported aiming to assist researchers who focus their research on lipid-based nanoparticles.

Enhanced solubility and biopharmaceutical performance of atorvastatin and metformin via electrospun polyvinylpyrrolidone-hyaluronic acid composite nanoparticles

The study was aimed to improve the aqueous solubility of atorvastatin (AT) and ameliorate permeability of metformin (MT) in a combination formulation, improving their oral bioavailability. Several AT-MT loaded polyvinylpyrrolidone (PVP) and hyaluronic acid (HA) based nanoparticles were prepared through electrospraying method (ES-NPs), and tested for physicochemical, in vitro, and in vivo parameters. Among the trialed formulations, a sample consisting of AT, MT, PVP, and HA at the weight ratio of 1/6.25/3.75/15 furnished the most satisfying solubility and release rate results. It enhanced approximately 10.3-fold and 3.6-fold solubility of AT as compared with AT powder and marketed product (Lipilow) in phosphate buffer pH = 6.8, respectively. Whereas, permeation of MT was 1.60-fold and 1.47-fold improved as compared with MT powder and marketed product (Glucophage), respectively. As compared with Lipilow, AUC _(0-∞) and C_max of AT with ES-NPs in rats were improved to 3.6-fold and 3.2-fold, respectively. Similarly, as compared with Glucophage, AUC _(0-∞) and C_max of MT were improved to 2.3-fold and 1.8-fold, respectively. Thus, ES-NPs significantly enhanced the solubility of AT (a BCS class II drug) and permeability of MT (a BCS class III drug) and might be a promising drug delivery system for co-delivery of these drugs.

Endocytic Uptake of Solid Lipid Nanoparticles by the Nasal Mucosa

Nanoparticles may provide unique therapeutic opportunities when administered via the nasal cavity, yet the primary uptake and transfer pathways for these particles within the nasal mucosa are not well understood. The endocytic pathways involved in the uptake of fluorescently labeled, (Nile Red) solid lipid nanoparticles (SLNs) of different sizes (~30, 60, and 150 nm) were studied using excised bovine olfactory and nasal respiratory tissues. Endocytic activity contributing to nanoparticle uptake was investigated using a variety of pharmacological inhibitors, but none of the inhibitors were able to completely eliminate the uptake of the SLNs. The continued uptake of nanoparticles following exposure to individual inhibitors suggests that a number of endocytic pathways work in combination to transfer nanoparticles into the nasal mucosa. Following exposure to the general metabolic inhibitors, 2,4-DNP and sodium azide, additional, non-energy-dependent pathways for nanoparticle uptake were also observed. While the smallest nanoparticles (30 nm) were the most resistant to the effects of pharmacologic inhibitors, the largest (150 nm) were still able to transfer significant amounts of the particles into the tissues. The rapid nanoparticle uptake observed demonstrates that these lipid particles are promising vehicles to accomplish both local and systemic drug delivery following nasal administration.

Docetaxel-loaded folate-modified TPGS-transfersomes for glioblastoma multiforme treatment

Glioblastoma multiforme (GBM) is a first primary Central Nervous System tumor with high incidence and lethality. Its treatment is hampered by the difficulty to overcome the blood-brain barrier (BBB) and by the non-specificity of chemotherapeutics to tumor cells. This study was based on the development characterization and in vitro efficacy of folate-modified TPGS transfersomes containing docetaxel (TF-DTX-FA) to improve GBM treatment. TF-DTX-FA and unmodified transfersomes (TF-DTX) were prepared through thin-film hydration followed by extrusion technique and characterized by physicochemical and in vitro studies. All formulations showed low particles sizes (below 200 nm), polydispersity index below 0.2, negative zeta potential (between -16.75 to -12.45 mV) and high encapsulation efficiency (78.72 ± 1.29% and 75.62 ± 0.05% for TF-DTX and TF-DTX-FA, respectively). Furthermore, cytotoxicity assay of TF-DTX-FA showed the high capacity of the nanocarriers to reduce the viability of U-87 MG in both 2D and 3D culture models, when compared with DTX commercial formulation and TF-DTX. In vitro cellular uptake assay indicated the selectivity of transfersomes to tumoral cells when compared to normal cells, and the higher ability of TF-DTX-FA to be internalized into 2D U-87 MG in comparison with TF-DTX (72.10 and 62.90%, respectively, after 24 h). Moreover, TF-DTX-FA showed higher permeability into 3D U-87 MG spheroid than TF-DTX, suggesting the potential FA modulation to target treatment of GBM.

Current State and Promising Opportunities on Pharmaceutical Approaches in the Treatment of Polymicrobial Diseases

In recent years, the emergence of newly identified acute and chronic infectious disorders caused by diverse combinations of pathogens, termed polymicrobial diseases, has had catastrophic consequences for humans. Antimicrobial agents have been clinically proven to be effective in the pharmacological treatment of polymicrobial diseases. Unfortunately, an increasing trend in the emergence of multi-drug-resistant pathogens and limited options for delivery of antimicrobial drugs might seriously impact humans' efforts to combat polymicrobial diseases in the coming decades. New antimicrobial agents with novel mechanism(s) of action and new pharmaceutical formulations or delivery systems to target infected sites are urgently required. In this review, we discuss the prospective use of novel antimicrobial compounds isolated from natural products to treat polymicrobial infections, mainly via mechanisms related to inhibition of biofilm formation. Drug-delivery systems developed to deliver antimicrobial compounds to both intracellular and extracellular pathogens are discussed. We further discuss the effectiveness of several biofilm-targeted delivery strategies to eliminate polymicrobial biofilms. At the end, we review the applications and promising opportunities for various drug-delivery systems, when compared to conventional antimicrobial therapy, as a pharmacological means to treat polymicrobial diseases.

Abdulbaqi I, Parumasivam T, Mohtar N, A. Wahab H. Advances in Nanocarriers for Effective Delivery of Docetaxel in the Treatment of Lung Cancer: An Overview

Docetaxel (DCX) is a highly effective chemotherapeutic drug used in the treatment of different types of cancer, including non-small cell lung cancer (NSCLC). The drug is known to have low oral bioavailability due to its low aqueous solubility, poor membrane permeability and susceptibility to hepatic first-pass metabolism. To mitigate these problems, DCX is administered via the intravenous route. Currently, DCX is commercially available as a single vial that contains polysorbate 80 and ethanol to solubilize the poorly soluble drug. However, this formulation causes short- and long-term side effects, including hypersensitivity, febrile neutropenia, fatigue, fluid retention, and peripheral neuropathy. DCX is also a substrate to the drug efflux pump P-glycoprotein (P-gp) that would reduce its concentration within the vicinity of the cells and lead to the development of drug resistance. Hence, the incorporation of DCX into various nanocarrier systems has garnered a significant amount of attention in recent years to overcome these drawbacks. The surfaces of these drug-delivery systems indeed can be functionalized by modification with different ligands for smart targeting towards cancerous cells. This article provides an overview of the latest nanotechnological approaches and the delivery systems that were developed for passive and active delivery of DCX via different routes of administration for the treatment of lung cancer.

Tailoring functional nanostructured lipid carriers for glioblastoma treatment with enhanced permeability through in-vitro 3D BBB/BBTB models

The blood-brain barrier (BBB) and blood-brain tumour barrier (BBTB) pose a significant challenge to drug delivery to brain tumours, including aggressive glioblastoma (GB). The present study rationally designed functional nanostructured lipid carriers (NLC) to tailor their BBB penetrating properties with high encapsulation of CNS negative chemotherapeutic drug docetaxel (DTX). We investigated the effect of four liquid lipids, propylene glycol monolaurate (Lauroglycol® 90), Capryol® propylene glycol monocaprylate, caprylocaproylmacrogol-8-glycerides (Labrasol®) and polyoxyl-15-hydroxystearate (Kolliphor® HS15) individually and in combination to develop NLCs with effective permeation across in-vitro 3D BBB model without alteration in the integrity of the barrier. With desirable spherical shape as revealed by TEM and an average particle size of 123.3 ± 0.642 nm and zeta potential of -32 mV, DTX-NLCs demonstrated excellent stability for six months in its freeze-dried form. The confocal microscopy along with flow cytometry data revealed higher internalisation of DTX-NLCs in U87MG over SVG P12 cells. Micropinocytosis was observed to be one of the dominant pathways for internalisation in U87MG cells while clathrin-mediated pathway was more predominat in patient-derived glioblastoma cells. The NLCs readily penetrated the actively proliferating peripheral cells on the surface of the 3D tumour spheroids as compared to the necrotic core. The DTX-NLCs induced cell arrest through G2/M phase with a significant decrease in the mitochondrial reserve capacity of cells. The NLCs circumvented BBTB with high permeability followed by accumulation in glioblastoma cells with patient-derived cells displaying ~2.4-fold higher uptake in comparison to U87MG when studied in a 3D in-vitro model of BBTB/GB. We envisage this simple and industrially feasible technology as a potential candidate to be developed as GB nanomedicine.

Cisplatin Prodrug-Loaded Nanoparticles Based on Physalis Mottle Virus for Cancer Therapy

Nanoparticle-based prodrugs offer an effective strategy to improve the safety and delivery of small-molecule therapeutics while reducing the risk of drug resistance. Here, we conjugated a maleimide-functionalized cisplatin prodrug containing Pt(IV) to the internal and/or external surface of virus-like particles (VLPs) derived from Physalis mottle virus (PhMV) to develop a pH-sensitive drug delivery system. The internally loaded and PEGylated VLPs (Pt-PhMVCy5.5-PEG) were taken up efficiently by cancer cells where they released platinum, presumably as a reduced, DNA-reactive Pt(II) complex, rapidly under acidic conditions in vitro (>80% in 30 h). The efficacy of the VLP-based drug delivery system was demonstrated against a panel of cancer cell lines, including cell lines resistant to platinum therapy. Furthermore, Pt-PhMVCy5.5-PEG successfully inhibited the growth of xenograft MDA-MB-231 breast tumors in vivo and significantly prolonged the survival of mice compared to free cisplatin and cisplatin-maleimide. Pt-PhMVCy5.5-PEG therefore appears promising as a prodrug to overcome the limitations of conventional platinum-based drugs for cancer therapy.

Lipid Drug Carriers for Cancer Therapeutics: An Insight into Lymphatic Targeting, P-gp, CYP3A4 Modulation and Bioavailability Enhancement

In the treatment of cancer, chemotherapy plays an important role though the efficacy of anti-cancer drug administered orally is limited, due to their poor solubility in physiological medium, inability to cross biological membrane, high Para-glycoprotein (P-gp) mediated drug efflux, and pre-systemic metabolism. These all factors cumulatively reduce drug exposure at the target site leading to multidrug resistance (MDR). Lipid based carriers systems has been explored to overcome solubility and permeability related issues of anti-cancer drugs. The lipid based formulations have also been reported to circumvent the effect of P-gp and CYP3A4. Further long chain triglycerides (LCT) has shown their ability to access Lymphatic route over Medium Chain Triglycerides, as the former has been extensively used for targeting anti-cancer drugs at proliferating cells through lymphatic route. Therefore this review tries to reflect the usefulness of lipid based drug carriers systems (viz. liposome, solid lipid nanoparticle, nano-lipid carriers, self-emulsifying, lipidic pro-drugs) in targeting lymphatic system and overcoming issues related to solubility and permeability of anti-cancer drugs. Moreover, we have also tried to reflect how critically lipid based carriers are important in maximizing therapeutic safety and efficacy of anti-cancer drugs.

A brief review on solid lipid nanoparticles: part and parcel of contemporary drug delivery systems

Drug delivery technology has a wide spectrum, which is continuously being upgraded at a stupendous speed. Different fabricated nanoparticles and drugs possessing low solubility and poor pharmacokinetic profiles are the two major substances extensively delivered to target sites. Among the colloidal carriers, nanolipid dispersions (liposomes, deformable liposomes, virosomes, ethosomes, and solid lipid nanoparticles) are ideal delivery systems with the advantages of biodegradation and nontoxicity. Among them, nano-structured lipid carriers and solid lipid nanoparticles (SLNs) are dominant, which can be modified to exhibit various advantages, compared to liposomes and polymeric nanoparticles. Nano-structured lipid carriers and SLNs are non-biotoxic since they are biodegradable. Besides, they are highly stable. Their (nano-structured lipid carriers and SLNs) morphology, structural characteristics, ingredients used for preparation, techniques for their production, and characterization using various methods are discussed in this review. Also, although nano-structured lipid carriers and SLNs are based on lipids and surfactants, the effect of these two matrixes to build excipients is also discussed together with their pharmacological significance with novel theranostic approaches, stability and storage.

Docetaxel-loaded solid lipid nanoparticles prevent tumor growth and lung metastasis of 4T1 murine mammary carcinoma cells

BACKGROUND

Metastasis causes the most breast cancer-related deaths in women. Here, we investigated the antitumor effect of solid lipid nanoparticles (SLN-DTX) when used in the treatment of metastatic breast tumors using 4T1-bearing BALB/c mice.

RESULTS

Solid lipid nanoparticles (SLNs) were produced using the high-energy method. Compritol 888 ATO was selected as the lipid matrix, and Pluronic F127 and Span 80 as the surfactants to stabilize nanoparticle dispersion. The particles had high stability for at least 120 days. The SLNs' dispersion size was 128 nm, their polydispersity index (PDI) was 0.2, and they showed a negative zeta potential. SLNs had high docetaxel (DTX) entrapment efficiency (86%), 2% of drug loading and showed a controlled drug-release profile. The half-maximal inhibitory concentration (IC₅₀) of SLN-DTX against 4T1 cells was more than 100 times lower than that of free DTX after 24 h treatment. In the cellular uptake test, SLN-DTX was taken into the cells significantly more than free DTX. The accumulation in the G2-M phase was significantly higher in cells treated with SLN-DTX (73.7%) than in cells treated with free DTX (23.0%), which induced subsequent apoptosis. TEM analysis revealed that SLN-DTX internalization is mediated by endocytosis, and fluorescence microscopy showed DTX induced microtubule damage. In vivo studies showed that SLN-DTX compared to free docetaxel exhibited higher antitumor efficacy by reducing tumor volume (p < 0.0001) and also prevented spontaneous lung metastasis in 4T1 tumor-bearing mice. Histological studies of lungs confirmed that treatment with SLN-DTX was able to prevent tumor. IL-6 serum levels, ki-67 and BCL-2 expression were analyzed and showed a remarkably strong reduction when used in a combined treatment.

CONCLUSIONS

These results indicate that DTX-loaded SLNs may be a promising carrier to treat breast cancer and in metastasis prevention.

Magnetic Hybrid Wax Nanocomposites as Externally Controlled Theranostic Vehicles: High MRI Enhancement and Synergistic Magnetically Assisted Thermo/Chemo Therapy

To fight against cancer, smarter drugs and drug delivery systems are required both to boost the efficiency of current treatments while reducing deleterious side effects, and combine diagnosis/monitoring with therapy (theranosis) in the search for the final goal of personalized medicine. This work presents the design, preparation, and proof-of-principle validation of a novel hybrid organic-inorganic nanocomposite joining together non-invasive imaging capabilities through magnetic resonance imaging and externally actuated therapeutic properties through a combination of chemo- and thermotherapy. The lipidic matrix of the nanocomposite was composed of carnauba wax, which was simultaneously dual loaded with magnetite nanoparticles and the anticancer drug Oncocalyxone A. Obtained formulations were fully characterized and showed outstanding performances as T₂ -contrast agents in magnetic resonance imaging (r₂ >800 mm^-1  s^-1 ), heat generating sources in magnetic hyperthermia (specific absorption rate, SAR>200 W g^-1 _Fe ), and magnetically responsive drug delivery vehicles. The potential of the designed formulations as theranostic agents was validated in vitro and results indicated a synergistic thermo/chemotherapeutic effect derived from heat generation and controlled drug delivery to cancer growth. Thereby, this external control over the drug delivery profile and the integrated imaging capability open the door to personalized cancer medicine and real-time monitoring of tumor progression.

Exploration of docetaxel palmitate and its solid lipid nanoparticles as a novel option for alleviating the rising concern of multi-drug resistance

Docetaxel (DTX), a widely prescribed anticancer agent, is now associated with increased instances of multidrug resistance. Also, being a problematic BCS class IV drug, it poses challenges for the formulators. Henceforth, it was envisioned to synthesize an analogue of DTX with a biocompatible lipid, i.e., palmitic acid. The in-silico studies (molecular docking and simulation) inferred lesser binding of docetaxel palmitate (DTX-PL) with P-gp vis-à-vis DTX and paclitaxel, indicating it to be a poor substrate for P-gp efflux. Solid lipid nanoparticles (SLNs) of the conjugate were prepared using various lipids, viz. palmitic acid, stearic acid, cetyl palmitate and glyceryl monostearate. The characterization studies for the nanocarrier were performed for the surface charge, drug payload, micromeritics, release pattern of drug and surface morphology. From the cytotoxicity assays on resistant MCF-7 cells, it was established that the new analogue offered substantially decreased IC₅₀ to that of DTX. Further, apoptosis assay also corroborated the results obtained in IC₅₀ determination wherein, SA-SLNs showed the highest apoptotic index than free DTX. The conjugate not only enhanced the solubility but also offered lower plasma protein binding and improved pharmacokinetic and pharmacodynamic effect for DTX loaded SA-SLNs in apt animal models, and lower affinity to P-gp efflux. The studies provide preliminary evidence and a ray of hope for a better candidate in its nano version for safer and effective cancer chemotherapy.