Folate/N-acetyl glucosamine conjugated mesoporous silica nanoparticles for targeting breast cancer cells: A comparative study

Unlocking the power of sugar: carbohydrate ligands as key players in nanotherapeutic-assisted targeted cancer therapy

Cancer cells need as much as 40-times more sugar than their normal cell counterparts. This sugar demand is attained by the excessive expression of inimitable transporters on the surface of cancer cells, driven by their voracious appetite for carbohydrates. Nanotechnological advances drive research utilizing ligand-directed therapeutics and diverse carbohydrate analogs. The precise delivery of these therapeutic cargos not only mitigates toxicity associated with chemotherapy but also reduces the grim toll of mortality and morbidity among patients. This in-depth review explores the potential of these ligands in advanced cancer treatment using nanoparticles. It offers a broader perspective beyond the usual ways we deliver drugs, potentially changing the way we fight cancer.

Targeting Breast Cancer with N-Acetyl-D-Glucosamine: Integrating Machine Learning and Cellular Assays for Promising Results

BACKGROUND

Breast cancer is a common cancer with high mortality rates. Early diagnosis is crucial for reducing the prognosis and mortality rates. Therefore, the development of alternative treatment options is necessary.

OBJECTIVE

This study aimed to investigate the inhibitory effect of N-acetyl-D-glucosamine (D-GlcNAc) on breast cancer using a machine learning method. The findings were further confirmed through assays on breast cancer cell lines.

METHODS

MCF-7 and 4T1 cell lines (ATCC) were cultured in the presence and absence of varying concentrations of D-GlcNAc (0.5 mM, 1 mM, 2 mM, and 4 mM) for 72 hours. A xenograft mouse model for breast cancer was established by injecting 4T1 cells into mammary glands. D-GlcNAc (2 mM) was administered intraperitoneally to mice daily for 28 days, and histopathological effects were evaluated at pre-tumoral and post-tumoral stages.

RESULTS

Treatment with 2 mM and 4 mM D-GlcNAc significantly decreased cell proliferation rates in MCF-7 and 4T1 cell lines and increased Fas expression. The number of apoptotic cells was significantly higher than untreated cell cultures (p < 0.01 - p < 0.0001). D-GlcNAc administration also considerably reduced tumour size, mitosis, and angiogenesis in the post-treatment group compared to the control breast cancer group (p < 0.01 - p < 0.0001). Additionally, molecular docking/dynamic analysis revealed a high binding affinity of D-GlcNAc to the marker protein HER2, which is involved in tumour progression and cell signalling.

CONCLUSION

Our study demonstrated the positive effect of D-GlcNAc administration on breast cancer cells, leading to increased apoptosis and Fas expression in the malignant phenotype. The binding affinity of D-GlcNAc to HER2 suggests a potential mechanism of action. These findings contribute to understanding D-GlcNAc as a potential anti-tumour agent for breast cancer treatment.

Research progress of nanomaterial drug delivery in tumor targeted therapy

Cancer is one of the most lethal diseases in human society, and its incidence is gradually increasing. However, the current tumor treatment often meets the problem of poor efficacy and big side effects. The unique physical and chemical properties of nanomaterials can target the delivery of drugs to tumors, which can improve the therapeutic effect while reducing the damage of drugs to normal cells. This makes nanomaterials become a hot topic in the field of biomedicine. This review summarizes the recent progress of nanomaterials in tumor targeted therapy.

Advanced cancer targeting using aptamer functionalized nanocarriers for site-specific cargo delivery

The non-specificity of standard anticancer therapies has profound detrimental consequences in clinical treatment. Therapeutic specificity can be precisely achieved using cutting-edge ligands. Small synthetic oligonucleotide-ligands chosen through Systematic evolution of ligands by exponential enrichment (SELEX) would be an unceasing innovation in using nucleic acids as aptamers, frequently referred to as "chemical antibodies." Aptamers act as externally controlled switching materials that can attach to various substrates, for example, membrane proteins or nucleic acid structures. Aptamers pose excellent specificity and affinity for target molecules and can be used as medicines to suppress tumor cell growth directly. The creation of aptamer-conjugated nanoconstructs has recently opened up innovative options in cancer therapy that are more effective and target tumor cells with minor toxicity to healthy tissues. This review focuses on a comprehensive description of the most capable classes of aptamer-tethered nanocarriers for precise recognition of cancer cells with significant development in proficiency, selectivity, and targetability for cancer therapy. Existing theranostic applications with the problems and future directions are also highlighted.

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.

Tumor Microenvironment Regulation and Cancer Targeting Therapy Based on Nanoparticles

Although we have made remarkable achievements in cancer awareness and medical technology, there are still tremendous increases in cancer incidence and mortality. However, most anti-tumor strategies, including immunotherapy, show low efficiency in clinical application. More and more evidence suggest that this low efficacy may be closely related to the immunosuppression of the tumor microenvironment (TME). The TME plays a significant role in tumorigenesis, development, and metastasis. Therefore, it is necessary to regulate the TME during antitumor therapy. Several strategies are developing to regulate the TME as inhibiting tumor angiogenesis, reversing tumor associated macrophage (TAM) phenotype, removing T cell immunosuppression, and so on. Among them, nanotechnology shows great potential for delivering regulators into TME, which further enhance the antitumor therapy efficacy. Properly designed nanomaterials can carry regulators and/or therapeutic agents to eligible locations or cells to trigger specific immune response and further kill tumor cells. Specifically, the designed nanoparticles could not only directly reverse the primary TME immunosuppression, but also induce effective systemic immune response, which would prevent niche formation before metastasis and inhibit tumor recurrence. In this review, we summarized the development of nanoparticles (NPs) for anti-cancer therapy, TME regulation, and tumor metastasis inhibition. We also discussed the prospect and potential of nanocarriers for cancer therapy.

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.

Recent Advances in Mesoporous Silica Nanoparticle-Mediated Drug Delivery for Breast Cancer Treatment

Breast cancer (BC) currently occupies the second rank in cancer-related global female deaths. Although consistent awareness and improved diagnosis have reduced mortality in recent years, late diagnosis and resistant response still limit the therapeutic efficacy of chemotherapeutic drugs (CDs), leading to relapse with consequent invasion and metastasis. Treatment with CDs is indeed well-versed but it is badly curtailed with accompanying side effects and inadequacies of site-specific drug delivery. As a result, drug carriers ensuring stealth delivery and sustained drug release with improved pharmacokinetics and biodistribution are urgently needed. Core-shell mesoporous silica nanoparticles (MSNPs) have recently been a cornerstone in this context, attributed to their high surface area, low density, robust functionalization, high drug loading capacity, size-shape-controlled functioning, and homogeneous shell architecture, enabling stealth drug delivery. Recent interest in using MSNPs as drug delivery vehicles has been due to their functionalization and size-shape-driven versatilities. With such insights, this article focuses on the preparation methods and drug delivery mechanisms of MSNPs, before discussing their emerging utility in BC treatment. The information compiled herein could consolidate the database for using inorganic nanoparticles (NPs) as BC drug delivery vehicles in terms of design, application and resolving post-therapy complications.

Eliminating host-guest incompatibility via enzyme mining enables the high-temperature production of N-acetylglucosamine

The host-guest incompatibility between a production host and non-native enzymes has posed an arduous challenge for synthetic biology, particularly between mesophile-derived enzymes and a thermophilic chassis. In the present study, we develop a thermophilic enzyme mining strategy comprising an automated co-evolution-based screening pipeline (http://cem.sjtu.edu.cn), computation-based enzyme characterization, and gene synthesis-based function validation. Using glucosamine-6-phosphate acetyltransferase (GNA1) as an example, we successfully mined four novel GNA1s with excellent thermostabilities and catalytic performances. Calculation and analysis based on AlphaFold2-generated structures were also conducted to uncover the mechanism underlying their excellent properties. Finally, our mined GNA1s were used to enable the high-temperature N-acetylglucosamine (GlcNAc) production with high titers of up to 119.3 g/L, with the aid of systems metabolic engineering and temperature programming. This study demonstrates the effectiveness of the enzyme mining strategy, highlighting the application prospects of mining new enzymes from massive databases and providing an effective solution for tackling host-guest incompatibility.

Tuning Mesoporous Silica Nanoparticles in Novel Avenues of Cancer Therapy

The global menace of cancer has led to an increased death toll in recent years. The constant evolution of cancer therapeutics with novel delivery systems has paved the way for translation of innovative therapeutics from bench to bedside. This review explains the significance of mesoporous silica nanoparticles (MSNs) as delivery vehicles with particular emphasis on cancer therapy, including novel opportunities for biomimetic therapeutics and vaccine delivery. Parameters governing MSN synthesis, therapeutic agent loading characteristics, along with tuning of MSN toward cancer cell specificity have been explained. The advent of MSN in nanotheranostics and its potential in forming nanocomposites for imaging purposes have been illustrated. Additionally, various hurdles encountered during the bench to bedside translation have been explained along with potential avenues to circumvent them. This also opens up new horizons in drug delivery, which could be useful to researchers in the years to come.

Triple-negative breast cancer drug resistance, durable efficacy, and cure: How advanced biological insights and emerging drug modalities could transform progress

INTRODUCTION

Triple-negative breast cancer (TNBC) is a heterogeneous disease characterized by the lack of estrogen receptor (ER), progesterone receptor (PR) and epidermal growth factor receptor 2 (HER2) and often associated with poor survival outcomes. The backbone of current treatments for TNBC relies on chemotherapy; however, resistance to cytotoxic agents is a commonly encountered hurdle to overcome.

AREAS COVERED

: Current understanding on the mechanisms involved in TNBC chemoresistance is evaluated and novel potential actionable targets and recently explored modalities for carrying and delivering chemotherapeutics are highlighted.

EXPERT OPINION

: A comprehensive identification of both genomic and functional TNBC signatures is required for a more definite categorization of the patients in order to prevent insensitivity to chemotherapy and therefore realize the full potential of precision-medicine approaches. In this scenario, cell-line-derived xenografts (CDX), patient-derived xenografts (PDX), patient-derived orthotopic xenografts (PDOX) and patient-derived organoids (PDO) are indispensable experimental models for evaluating the efficacy of drug candidates and predicting the therapeutic response. The combination of increasingly sensitive "omics" technologies, computational algorithms and innovative drug modalities may accelerate the successful translation of novel candidate TNBC targets from basic research to clinical settings, thus contributing to reach optimal clinical output, with lower side effects and reduced resistance.

siRNA delivery using intelligent chitosan-capped mesoporous silica nanoparticles for overcoming multidrug resistance in malignant carcinoma cells

Although siRNA is a promising technology for cancer gene therapy, effective cytoplasmic delivery has remained a significant challenge. In this paper, a potent siRNA transfer system with active targeting moieties toward cancer cells and a high loading capacity is introduced to inhibit drug resistance. Mesoporous silica nanoparticles are of great potential for developing targeted gene delivery. Amino-modified MSNs (NH₂-MSNs) were synthesized using a modified sol–gel method and characterized by FTIR, BET, TEM, SEM, X-ray diffraction, DLS, and ¹H-NMR. MDR1-siRNA was loaded within NH₂-MSNs, and the resulting negative surface was capped by functionalized chitosan as a protective layer. Targeting moieties such as TAT and folate were anchored to chitosan via PEG-spacers. The loading capacity of siRNA and the protective effect of chitosan for siRNA were determined by gel retardation assay. MTT assay, flow cytometry, real-time PCR, and western blot were performed to study the cytotoxicity, cellular uptake assay, targeting evaluation, and MDR1 knockdown efficiency. The synthesized NH₂-MSNs had a particle size of ≈ 100 nm and pore size of ≈ 5 nm. siRNA was loaded into NH₂-MSNs with a high loading capacity of 20% w/w. Chitosan coating on the surface of siRNA-NH₂-MSNs significantly improved the siRNA protection against enzyme activity compared to naked siRNA-NH₂-MSNs. MSNs and modified MSNs did not exhibit significant cytotoxicity at therapeutic concentrations in the EPG85.257-RDB and HeLa-RDB lines. The folate-conjugated nanoparticles showed a cellular uptake of around two times higher in folate receptor-rich HeLa-RDB than EPG85.257-RDB cells. The chitosan-coated siRNA-NH2-MSNs produced decreased MDR1 transcript and protein levels in HeLa-RDB by 0.20 and 0.48-fold, respectively. The results demonstrated that functionalized chitosan-coated siRNA-MSNs could be a promising carrier for targeted cancer therapy. Folate-targeted nanoparticles were specifically harvested by folate receptor-rich HeLa-RDB and produced a chemosensitized phenotype of the multidrug-resistant cancer cells.

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.

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 (Q_8h, 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.

Spray drying as an efficient route for synthesis of silica nanoparticles-sodium alginate biohybrid drug carrier of doxorubicin

Biohybrids (a combination of biological material and inorganic nanoparticles) offer a number of advantages like improved functionality over conventional materials.Thus, to understand the practical application of biohybrids as drug carriers, a biohybrid drug carrier of colloidal silica nanoparticles (NP)-sodium alginate loaded with doxorubicin (Dox-biohybrid) was synthesized by evaporation induced self-assembly (EISA) using spray drying technique. Further, the morphology, size and interactions between various components of the biohybrid were studied through SEM, DLS and FTIR techniques. The drug loading efficiency, release profile, cellular uptake and cytotoxicity of Dox-biohybrid was investigated and compared with free Dox. The drug loading efficiencies of Dox-biohybrid, Dox-silica NP and Dox-sodium alginate were 93.7 %, 96.4 % and 88.3 % respectively. In vitro release study showed a slow release of entrapped Dox from Dox-biohybrid as compared to other carriers. This release was also pH-responsive with significantly higher cumulative drug release at pH 5.5 (cancer microenvironment) in comparison to pH 7.4 (physiological conditions). The empty biohybrid carrier did not show cytotoxicity to normal mouse lymphocytes upto a concentration of 25 μg/mL which was used further. The uptake of Dox from Dox-biohybrid by A549 cells was more than 2fold as compared to uptake from free Dox. in vitro viability assay revealed that treatment of lung carcinoma A549 cells with Dox-biohybrid resulted in 50 % loss of cell viability at 500 nM, compared to only 12 % loss with free Dox. Thus, we report the synthesis of a novel biohybrid drug delivery system by means of spray drying process that has promising applications in cancer treatment.

Recent Progress of Nanocarrier-Based Therapy for Solid Malignancies

Conventional chemotherapy is still an important option of cancer treatment, but it has poor cell selectivity, severe side effects, and drug resistance. Utilizing nanoparticles (NPs) to improve the therapeutic effect of chemotherapeutic drugs has been highlighted in recent years. Nanotechnology dramatically changed the face of oncology by high loading capacity, less toxicity, targeted delivery of drugs, increased uptake to target sites, and optimized pharmacokinetic patterns of traditional drugs. At present, research is being envisaged in the field of novel nano-pharmaceutical design, such as liposome, polymer NPs, bio-NPs, and inorganic NPs, so as to make chemotherapy effective and long-lasting. Till now, a number of studies have been conducted using a wide range of nanocarriers for the treatment of solid tumors including lung, breast, pancreas, brain, and liver. To provide a reference for the further application of chemodrug-loaded nanoformulations, this review gives an overview of the recent development of nanocarriers, and the updated status of their use in the treatment of several solid tumors.

Formulation and characterization of folate receptor-targeted PEGylated liposome encapsulating bioactive compounds from Kappaphycus alvarezii for cancer therapy

This study aimed to formulate and characterize the folate receptor-targeted PEGylated liposome encapsulating bioactive compounds from Kappaphycus alvarezii to enhance the anticancer activity. Twenty valued bioactive compounds (3-hydroxy benzoicacid, gallicacid, chlorogenicacid, cinnamicacid, artemiseole, hydrazine carbothioamide, etc.,) are confirmed from methanol extract of K. alvarezii using analytical techniques like HPLC and GC-MS. The delivery of bioactive compounds of K. alvarezii via naturally overexpressed folate receptor (FR) to FR-positive breast cancer cells was studied. FR targeted PEGylated liposome was constructed by modified thin-film hydration technique using FA-PEG-DSPE/cholesterol/DSPC (5:40:55) and bioactive compounds of K. alvarezii was encapsulated. Their morphology, size, shape, physiological stability and drug release kinetics were studied. The study reports of K. alvarezii extract-encapsulated PEGylated liposome showed spherical shaped particles with amorphous in nature. The mean diameter of K. alvarezii extract-encapsulated PEGylated and FA-conjugated PEGylated liposomes was found to be 110 ± 6 nm and 140 ± 5 nm, respectively. Based on the stability studies, it could be confirmed that FA-conjugated PEGylated liposome was highly stable in various physiological buffer medium. FA-conjugated PEGylated liposome can steadily release the bioactive compounds of K. alvarezii extract in acidic medium (pH 5.4). MTT assay demonstrated the concentration-dependent cytotoxicity against MCF-7 cells after 24 h with IC₅₀ of 81 µg/mL. Also, PEGylated liposome enhanced the delivery of K. alvarezii extract in MCF-7 cells. After treatment, typical apoptotic morphology of condensed nuclei and distorted membrane bodies was picturized. Additionally, PEGylated liposome targets the mitochondria of MCF-7 cells and significantly increased the level of ROS and contributes to the damage of mitochondrial transmembrane potential. Hence, PEGylated liposome could positively deliver the bioactive compounds of K. alvarezii extract into FR-positive breast cancer cells (MCF-7) and exhibit great potential in anticancer therapy.

Folic acid (FA)-conjugated mesoporous silica nanoparticles combined with MRP-1 siRNA improves the suppressive effects of myricetin on non-small cell lung cancer (NSCLC)

Non-small cell lung cancer (NSCLC) is a common diagnosed cancer disease worldwide and its management remains a challenge. Synergistic cancer therapeutic strategy is interesting for multiple advantages, such as excellent targeting accuracy, low side effects, and promoted therapeutic efficiency. In the present study, myricetin (Myr)-loaded mesoporous silica nanoparticles (MSN) combined with multidrug resistance protein (MRP-1) siRNA was prepared. The surface of the synthesized nanoparticles was modified with folic acid (FA) to promote the therapeutic efficiency of Myr for the treatment of NSCLC. The collected particles were nano-sized and showed a sustained release of Myr in the physiological conditions. FA-conjugated nanoformulations displayed a significant uptake in lung cancer cells compared with that of the non-targeted nanoparticles. The in vitro drug release results suggested a sustained release in FA-conjugated MSN with Myr and MRP-1 nanoparticles compared to the free Myr and MSN combined with MRP-1/Myr. Treatments with FA-conjugated MSN combined with Myr and MRP-1 markedly reduced the cell viability of lung cancer cell lines, including A549 and NCI-H1299, which was accompanied with the decreased number of colony formation. In addition, FA-conjugated MSN loaded with Myr and MRP-1 significantly induced apoptosis in lung cancer cells, along with up-regulated expression levels of cleaved Caspase-3 and PARP. In vivo fluorescence results demonstrated that FA-conjugated MSN with Myr and MRP-1 nanoparticles could specifically accumulate at tumor sites. Compared with free Myr and MSN combined with MRP-1/Myr nanoparticles, FA-conjugated MSN loaded with Myr and MRP-1 nanoparticles could more effectively suppress tumor growth with little side effects. Overall, FA-conjugated nanoparticulate system could provide a novel and effective platform for the treatment of NSCLC.

A NAG-Guided Nano-Delivery System for Redox- and pH-Triggered Intracellularly Sequential Drug Release in Cancer Cells

Aim

Sequential treatment with paclitaxel (PTXL) and gemcitabine (GEM) is considered clinically beneficial for non-small-cell lung cancer. This study aimed to investigate the effectiveness of a nano-system capable of sequential release of PTXL and GEM within cancer cells.

Methods

PTXL-ss-poly(6-O-methacryloyl-d-galactopyranose)-GEM (PTXL-ss-PMAGP-GEM) was designed by conjugating PMAGP with PTXL via disulfide bonds (-ss-), while GEM via succinic anhydride (PTXL:GEM=1:3). An amphiphilic block copolymer N-acetyl-d-glucosamine(NAG)-poly(styrene-alt-maleic anhydride)₅₈-b-polystyrene₁₃₀ acted as a targeting moiety and emulsifier in formation of nanostructures (NLCs).

Results

The PTXL-ss-PMAGP-GEM/NAG NLCs (119.6 nm) provided a sequential in vitro release of, first PTXL (redox-triggered), then GEM (pH-triggered). The redox- and pH-sensitive NLCs readily distributed homogenously in the cytoplasm. NAG augmented the uptake of NLCs by the cancer cells and tumor accumulation. PTXL-ss-PMAGP-GEM/NAG NLCs exhibited synergistic cytotoxicity in vitro and strongest antitumor effects in tumor-bearing mice compared to NLCs lacking pH/redox sensitivities or free drug combination.

Conclusion

This study demonstrated the abilities of PTXL-ss-PMAGP-GEM/NAG NLCs to achieve synergistic antitumor effect by targeted intracellularly sequential drug release.

Erlotinib-loaded carboxymethyl temarind gum semi-interpenetrating nanocomposites

Erlotinib-loaded carboxymethyl temarind gum-g-poly(N-isopropylacrylamide)-montmorillonite based semi-IPN nanocomposites were synthesized and characterized for their in vitro performances for lung cancer therapy. The placebo matrices exhibited outstanding biodegradability and pH-dependent swelling profiles. The molar mass (M¯ c) between the crosslinks of these composites was declined with temperature. The solid state characterization confirmed the semi-IPN architecture of these scaffolds. The corresponding drug-loaded formulations displayed excellent drug-trapping capacity (DEE, 86-97 %) with acceptable zeta potential (-16 to -13 mV) and diameter (967-646 nm). These formulations conferred sustained drug elution profiles (Q_8h, 77-99 %) with an initial burst release. The drug release profile of the optimized formulation (F-3) was best fitted in the first order kinetic model with Fickian diffusion driven mechanism. The mucin adsorption to F-3 followed Langmuir isotherms. The results of MTT assay, AO/EB staining and confocal analyses revealed that the ERL-loaded formulation suppressed A549 cell proliferation and induced apoptosis more effectively than pristine drug.

Decapeptide functionalized targeted mesoporous silica nanoparticles with doxorubicin exhibit enhanced apoptotic effect in breast and prostate cancer cells

BACKGROUND

Considering the increase in cancer cases and number of deaths per year worldwide, development of potential therapeutics is imperative. Mesoporous silica nanoparticles (MSNPs) are among the potential nanocarriers having unique properties for drug delivery. Doxorubicin (DOX), being the most commonly used drug, can be efficiently delivered to gonadotropin-releasing hormone (GnRH)-overexpressing cancer cells using functionalized MSNPs.

AIM

We report the development of decapeptide-conjugated MSNPs loaded with DOX for the targeted drug delivery in breast and prostate cancer cells.

MATERIALS AND METHODS

MSNPs were synthesized and subsequently functionalized with an analog of GnRH by using a heterobifunctional polyethylene glycol as a linker. These targeted MSNPs were then characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, and Raman spectroscopy. An anticancer drug DOX was loaded and then characterized for drug loading. DOX-loaded nanocarriers were then studied for their cellular uptake using confocal microscopy. The cytotoxicity of DOX-loaded targeted MSNPs and DOX-loaded bare MSNPs was studied by performing MTT assay on MCF-7 (breast cancer) and LNCaP (prostate cancer) cells. Further, acridine orange/ethidium bromide staining, as well as flow cytometry, was performed to confirm the apoptotic mode of cancer cell death.

RESULTS

MSNPs were conjugated with polyethylene glycol as well as an agonist of GnRH and subsequently loaded with DOX. These targeted and bare MSNPs showed excellent porous structure and loading of DOX. Further, higher uptake of DOX-loaded targeted MSNPs was observed as compared to DOX-loaded bare MSNPs in GnRH-overexpressing breast (MCF-7) and prostate (LNCaP) cancer cells. The targeted MSNPs also showed significantly higher (P<0.001) cytotoxicity than DOX-loaded bare MSNPs at different time points. After 48 hours of treatment, the IC50 value for DOX-loaded targeted MSNPs was found to be 0.44 and 0.43 µM in MCF-7 and LNCaP cells, respectively. Acridine orange/ethidium bromide staining and flow cytometry analysis further confirmed the pathway of cell death through apoptosis.

CONCLUSION

This study suggests GnRH analog-conjugated targeted MSNPs can be the suitable and promising approach for targeted drug delivery in all hormone-dependent cancer cells.

Mesoporous silica nanoparticles as cutting-edge theranostics: Advancement from merely a carrier to tailor-made smart delivery platform

Large surface area, uniform and tunable pore size, high pore volume and low mass density- such attractive features of Mesoporous silica nanoparticles (MSNPs) have compelled researchers to explore the biomedical potential of this nano-material. Recently gained interest in MSNPs have been due to their tremendous potential in cancer therapy and imaging. Last several years have witnessed a rapid development in engineering functionalized MSNPs with various types of functional groups integrated into the system for imaging and therapeutic applications. Although their potential for drug delivery application has been studied since the year 2000, still a major challenge is to improve drug loading capacity and in vivo targeting with minimal side-effects to major organs. In this review article, the recent development of MSNPs as a therapeutic and diagnostic platform has been detailed out with emphasis on drug and bio-macromolecule delivery/co-delivery, bio-imaging and detoxification.

cRGD functionalised nanocarriers for targeted delivery of bioactives

The integrins α_vβ₃ play a very imperative role in angiogenesis and are overexpressed in endothelial cells of the tumour. Recent years have witnessed huge exploration in the field of α_vβ₃ integrin-mediated bioactive targeting for treatment of cancer. In these studies, the cRGD peptide has been employed extensively owing to their binding capacity to the α_vβ₃ integrin. Principally, RGD-based approaches comprise of antagonist molecules of the RGD sequence, drug-RGD conjugates, and most importantly tethering of the nanocarrier surface with the RGD peptide as targeting ligand. Targeting tumour vasculature or cells via cRGD conjugated nanocarriers have emerged as a promising technique for delivering chemotherapeutic drugs and imaging agents for cancer theranostics. In this review, primary emphasis has been given on the application of cRGD-anchored nanocarriers for targeted delivery of drugs, imaging agents, etc. for tumour therapy.

Metabolic engineering of carbon overflow metabolism of Bacillus subtilis for improved N-acetyl-glucosamine production

Bacillus subtilis is widely used as cell factories for the production of important industrial biochemicals. Although many studies have demonstrated the effects of organic acidic byproducts, such as acetate, on microbial fermentation, little is known about the effects of blocking the neutral byproduct overflow, such as acetoin, on bioproduction. In this study, we focused on the influences of modulating overflow metabolism on the production of N-acetyl-d-glucosamine (GlcNAc) in engineered B. subtilis. We found that acetoin overflow competes with GlcNAc production, and blocking acetoin overflow increased GlcNAc titer and yield by 1.38- and 1.39-fold, reaching 48.9 g/L and 0.32 g GlcNAc/g glucose, respectively. Further blocking acetate overflow inhibited cell growth and GlcNAc production may be induced by inhibiting glucose uptake. Taken together, our results show that blocking acetoin overflow is a promising strategy for enhancing GlcNAc production. The strategies developed in this work may be useful for engineering strains of B. subtilis for producing other important biochemicals.

Mesoporous Silica Nanoparticles

Integration of nanotechnology and biomedicine has offered great opportunities for the development of nanoscaled therapeutic platforms. Amongst various nanocarriers, mesoporous silica nanoparticles (MSNs) is one of the most developed and promising inorganic materials-based drug delivery system for clinical translations due to their simple composition and nanoporous structure. MSNs possess unique structural features, for example, well-defined morphology, large surface areas, uniform size, controllable structure, flexible pore volume, tunable pore sizes, extraordinarily high loading efficiency, and excellent biocompatibility. Progress in structure control and functionalization may endow MSNs with functionalities that enable medical applications of these integrated nanoparticles such as molecularly targeted drug delivery, multicomponent synergistic therapy, in vivo imaging and therapeutic capability, on-demand/stimuli-responsive drug release, etc. In this chapter, the authors overview MSNs' characteristics and the scientific efforts developed till date involving drug delivery and biomedical applications.