Mesoporous Silica Nanoparticles as Carriers for Biomolecules in Cancer Therapy.

Mesoporous silica nanoparticles (MSNs) offer many advantageous properties for applications in the field of nanobiotechnology. Loading of small molecules into MSNs is straightforward and widely applied, but with the upswing of both research and commercial interest in biological drugs in recent years, also biomacromolecules have been loaded into MSNs for delivery purposes. MSNs possess many critical properties making them a promising and versatile carrier for biomacromolecular delivery. In this chapter, we review the effects of the various structural parameters of MSNs on the effective loading of biomacromolecular therapeutics, with focus on maintaining stability and drug delivery performance. We also emphasize recent studies involving the use of MSNs in the delivery of biomacromolecular drugs, especially for cancer treatment.

Development and characterization of cationic solid lipid nanoparticles for co-delivery of pemetrexed and miR-21 antisense oligonucleotide to glioblastoma cells.

The practical use of solid lipid nanoparticles (SLNs) in research has been highlighted in the literature, but few reports have combined SLNs with miRNA-based therapy and chemotherapy. We aimed to prepare cationic SLNs (cSLNs) to load anti-miR-21 oligonucleotide and pemetrexed for glioblastoma therapy in vitro. cSLNs were employed to encapsulate both pemetrexed and anti-miR-21 by a high-pressure homogenization method, and then the properties of cSLNs were characterized. We studied cellular uptake and cytotoxicity properties of cSLNs in U87MG cells. cSLNs were 124.9 ± 1.6 nm in size and 27.3 ± 1.6 mV in zeta potential with spherical morphology in the TEM image. cSLNs uptake by U87MG cells was increased significantly higher and more effective than free pemetrexed. These findings suggest that cSLNs represent a potential new approach for carrying both pemetrexed and anti-miR-21 for glioblastoma therapy.

Co-delivery of pemetrexed and miR-21 antisense oligonucleotide by lipid-polymer hybrid nanoparticles and effects on glioblastoma cells.

Combination therapy using anticancer drugs and nucleic acid is a more promising strategy to overcome multidrug resistance in cancer and to enhance apoptosis. In this study, lipid-polymer hybrid nanoparticles (LPNs), which contain both pemetrexed and miR-21 antisense oligonucleotide (anti-miR-21), have been developed for treatment of glioblastoma, the most aggressive type of brain tumor. Prepared LPNs have been well characterized by particle size distribution and zeta potential measurements, determination of encapsulation efficiency, and in vitro release experiments. Morphology of LPNs was determined by transmission electron microscopy. LPNs had a hydrodynamic size below 100 nm and exhibited sustained release of pemetrexed up to 10 h. Encapsulation of pemetrexed in LPNs increased cellular uptake from 6% to 78%. Results of confocal microscopy analysis have shown that co-delivery of anti-miR-21 significantly improved accumulation of LPNs in the nucleus of U87MG cells. Nevertheless, more effective cytotoxicity results could not be obtained due to low concentration of anti-miR-21, loaded in LPNs. We expect that the effective drug delivery systems can be obtained with higher concentration of anti-miR-21 for the treatment of glioblastoma.

Design of Polymeric Nanoparticles for Theranostic Delivery of Capsaicin as Anti-Cancer Drug and Fluorescent Nitrogen-Doped Graphene Quantum Dots.

In recent years, multifunctional nanocarriers that provide simultaneous drug delivery and imaging have attracted enormous attention, especially in cancer treatment. In this research, a biocompatible fluorescent multifunctional nanocarrier is designed for the co-delivery of capsaicin (CPS) and nitrogen-doped graphene quantum dots (N-GQDs) using the pH sensitive amphiphilic block copolymer (poly(2-ethyl-2-oxazoline)-b-poly(ε-caprolactone), PEtOx-b-PCL). The effects of the critical formulation parameters (the amount of copolymer, the concentration of poly(vinyl alcohol) (PVA) as a stabilizing agent in the inner aqueous phase, and volume of the inner phase) are evaluated to achieve optimal nanoparticle (NP) properties using Central Composite Design. The optimized NPs demonstrated a desirable size distribution (167.8 ± 1.4 nm) with a negative surface charge (-19.9 ± 0.4) and a suitable loading capacity for CPS (70.80 ± 0.05%). The CPS & N-GQD NPs are found to have remarkable toxicity on human breast adenocarcinoma cell line (MCF-7). The solid fluorescent signal is acquired from cells containing multifunctional NPs, according to the confocal microscope imaging results, confirming the significant cellular uptake. This research illustrates the enormous potential for cellular imaging and enhanced cancer therapy offered by multifunctional nanocarriers that combine drug substances with the novel fluorescent agents.

Design and in vitro/in vivo Evaluation of Polyelectrolyte Complex Nanoparticles Filled in Enteric-Coated Capsules for Oral Delivery of Insulin.

Insulin is one of the most important drugs in the treatment of diabetes. There is an increasing interest in the oral administration of insulin as it mimics the physiological pathway and potentially reduces the side effects associated with subcutaneous injection. Therefore, insulin-loaded polyelectrolyte complex (PEC) nanoparticles were prepared by the ionic cross-linking method using protamine sulfate as the polycationic and sodium alginate as the anionic polymer. Taguchi experimental design was used for the optimization of nanoparticles by varying the concentration of sodium alginate, the mass ratio of sodium alginate to protamine, and the amount of insulin. The optimized nanoparticle formulation was used for further in vitro characterization. Then, insulin-loaded PEC nanoparticles were placed in hard gelatin capsules and the capsules were enteric-coated by Eudragit L100-55 (PEC-eCAPs). Hypoglycemic effects PEC-eCAPs were determined in vivo by oral administration to diabetic rats. Furthermore, in vivo distribution of PEC nanoparticles was evaluated by fluorescein isothiocyanate (FITC) labelled nanoparticles. The experimental design led to nanoparticles with a size of 194.4 nm and a polydispersity index (PDI) of 0.31. The encapsulation efficiency (EE) was calculated as 95.96%. In vivo studies showed that PEC-eCAPs significantly reduced the blood glucose level of rats at the 8th hour compared to oral insulin solution. It was concluded that PEC nanoparticles loaded into enteric-coated hard gelatin capsules provide a promising delivery system for the oral administration of insulin.

Microfluidic-Assisted Fabrication of Dual-Coated pH-Sensitive Mesoporous Silica Nanoparticles for Protein Delivery.

Microfluidics has become a popular method for constructing nanosystems in recent years, but it can also be used to coat other materials with polymeric layers. The polymeric coating may serve as a diffusion barrier against hydrophilic compounds, a responsive layer for controlled release, or a functional layer introduced to a nanocomposite for achieving the desired surface chemistry. In this study, mesoporous silica nanoparticles (MSNs) with enlarged pores were synthesized to achieve high protein loading combined with high protein retention within the MSN system with the aid of a microfluidic coating. Thus, MSNs were first coated with a cationic polyelectrolyte, poly (diallyldimethylammonium chloride) (PDDMA), and to potentially further control the protein release, a second coating of a pH-sensitive polymer (spermine-modified acetylated dextran, SpAcDEX) was deposited by a designed microfluidic device. The protective PDDMA layer was first formed under aqueous conditions, whereby the bioactivity of the protein could be maintained. The second coating polymer, SpAcDEX, was preferred to provide pH-sensitive protein release in the intracellular environment. The optimized formulation was effectively taken up by the cells along with the loaded protein cargo. This proof-of-concept study thus demonstrated that the use of microfluidic technologies for the design of protein delivery systems has great potential in terms of creating multicomponent systems and preserving protein stability.

Development of Zoledronic Acid Containing Biomaterials for Enhanced Guided Bone Regeneration.

In recent years, biomaterial-based treatments, also called guided bone regeneration (GBR), which aim to establish a bone regeneration site and prevent the migration of gingival connective tissue and / or peripheral epithelium through the defective area during periodontal surgical procedures have come to the fore. In this report, we have developed a nanoparticle bearing thermosensitive in situ gel formulation of Pluronic F127 and poly(D,L-lactic acid) based membrane to reveal their utilization at GBR by in-vivo applications. In addition, the encouragement of the bone formation in defect area via inhibition of osteoclastic activity is intended by fabrication these biodegradable biomaterials at a lowered Zoledronic Acid (ZA) dose. Both of the developed materials remained stable under specified stability conditions (25 °C, 6 months) and provided the extended release profile of ZA. The in-vivo efficacy of nanoparticle bearing in situ gel formulation, membrane formulation and simultaneous application for guided bone regeneration was investigated in New Zealand female rabbits with a critical size defect of 0.5 × 0.5 cm in the tibia bone for eight weeks. Based on the histopathological findings, lamellar bone and primarily woven bone formations were observed after 8 weeks of post-implantation of both formulations, while fibrosis was detected only in the untreated group. Lamellar bone growth was remarkably achieved just four weeks after the simultaneous application of formulations. Consequently, the simultaneous application of ZA-membrane and ZA-nanoparticles loaded in-situ gel formulations offers enhanced and faster GBR therapy alternatives.

A robust optimization approach for the breast cancer targeted design of PEtOx-b-PLA polymersomes.

The equipping of nanoparticles with the peptide moiety recognizing a particular receptor, enables cell or tissue-specific targeting, therefore the optimization of the targeted nanoparticles is a key factor in the formulation design process. In this paper, we report the optimization concept of Doxorubicin encapsulating PEtOx-b-PLA polymersome formulation equipped with Peptide18, which is a breast cancer recognizing tumor homing peptide, and the unveiling of the cell-specific delivery potential. The most dominant formulation parameters, which are the polymer to Doxorubicin mass ratio (w/w) and the aqueous to organic phase ratio (v/v), were optimized using Central Composite Design (CCD) based Response Surface Methodology. The characteristics of optimum polymersome formulation were determined as the hydrodynamic diameter of 146.35 nm, the PDI value of 0.136, and the encapsulation efficiency of 57.11% and TEM imaging, which are in agreement with the DLS data, showed the spherical morphology of the polymersomes. In order to demonstrate the breast cancer-specific delivery of targeted polymersomes, the flow cytometry and confocal microscopy analyses were carried out. The targeted polymersomes were accumulated 8 times higher in AU565 cells compared to MCF10A cells and the intracellular Doxorubicin was almost 10 times higher in AU565 cells. The CCD-mediated optimized targeted polymersomes proposed in this report holds the promise of targeted therapy for breast cancer and can be potentially used for the development of novel treatments.

Stimuli-Responsive, Plasmonic Nanogel for Dual Delivery of Curcumin and Photothermal Therapy for Cancer Treatment.

Nanogels (Ng) are crosslinked polymer-based hydrogel nanoparticles considered to be next-generation drug delivery systems due to their superior properties, including high drug loading capacity, low toxicity, and stimuli responsiveness. In this study, dually thermo-pH-responsive plasmonic nanogel (AuNP@Ng) was synthesized by grafting poly (N-isopropyl acrylamide) (PNIPAM) to chitosan (CS) in the presence of a chemical crosslinker to serve as a drug carrier system. The nanogel was further incorporated with gold nanoparticles (AuNP) to provide simultaneous drug delivery and photothermal therapy (PTT). Curcumin's (Cur) low water solubility and low bioavailability are the biggest obstacles to effective use of curcumin for anticancer therapy, and these obstacles can be overcome by utilizing an efficient delivery system. Therefore, curcumin was chosen as a model drug to be loaded into the nanogel for enhancing the anticancer efficiency, and further, its therapeutic efficiency was enhanced by PTT of the formulated AuNP@Ng. Thorough characterization of Ng based on CS and PNIPAM was conducted to confirm successful synthesis. Furthermore, photothermal properties and swelling ratio of fabricated nanoparticles were evaluated. Morphology and size measurements of nanogel were determined by transmission electron microscopy (TEM), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). Nanogel was found to have a hydrodynamic size of ~167 nm and exhibited sustained release of curcumin up to 72 h with dual thermo-pH responsive drug release behavior, as examined under different temperature and pH conditions. Cytocompatibility of plasmonic nanogel was evaluated on MDA-MB-231 human breast cancer and non-tumorigenic MCF 10A cell lines, and the findings indicated the nanogel formulation to be cytocompatible. Nanoparticle uptake studies showed high internalization of nanoparticles in cancer cells when compared with non-tumorigenic cells and confocal microscopy further demonstrated that AuNP@Ng were internalized into the MDA-MB-231 cancer cells via endosomal route. In vitro cytotoxicity studies revealed dose-dependent and time-dependent drug delivery of curcumin loaded AuNP@Ng/Cur. Furthermore, the developed nanoparticles showed an improved chemotherapy efficacy when irradiated with near-infrared (NIR) laser (808 nm) in vitro. This work revealed that synthesized plasmonic nanogel loaded with curcumin (AuNP@Ng/Cur) can act as stimuli-responsive nanocarriers, having potential for dual therapy i.e., delivery of hydrophobic drug and photothermal therapy.

Guided bone regeneration by the development of alendronate sodium loaded in-situ gel and membrane formulations.

Biocompatible materials applied in guided bone regeneration are needed to prevent leakage caused by the invasion of peripheral epithelium. (2.1) The aim of this study is to develop a thermosensitive in situ gel system containing alendronate sodium loaded PLGA nanoparticles and alendronate sodium loaded membranes for guided bone regeneration. Thermosensitive Pluronic F127 gel system was preferred to prevent soft tissue migration to the defect site and prolong the residence time of the nanoparticles in this region. In situ gel system was combined with membrane formulation to enhance bone regenaration activity. Efficacy of combination system was investigated by implanting in 0.5 × 0.5 cm critical size defect in tibia of New Zealand female rabbits. According to the histopathological results, fibroblast formations were found at defect area after 6 weeks of post implantation. In contrast, treatment with the combination of in-situ gel containing nanoparticles with membrane provided woven bone formation with mature bone after 4 weeks of post implantation. As a results, the combination of in-situ gel formulation containing alendronate sodium-loaded nanoparticles with membrane formulation could be effectively applided for guided bone regeneration.

Investigation on formulation parameters of donepezil HCl loaded solid lipid nanoparticles

Abstract Donepezil-HCl is a member of the acetylcholinesterase inhibitors that is indicated for the symptomatic treatment of Alzheimer's disease (AD) and has many side effects. In this study, to reduce the side effects of Donepezil-HCl and increase the penetration of the drug through the blood-brain barrier, we aimed to design a solid lipid nanoparticle (SLN) formulation. The effects of the different formulation parameters, such as homogenization speed, sonication time, lipid and drug concentration, surfactant type and concentration, and volume of the aqueous phase, were assessed for optimization. The particle size and PDI increased with increasing lipid concentration but decreased with increasing amounts of surfactant (Tween 80) and co-surfactant (lecithin). When the homogenization rate and sonication time increased, the particle size decreased and the encapsulation efficiency increased. The optimized formulation exhibited particle size, PDI, encapsulation efficiency, and zeta potential of 87.2±0.11 nm; 0.22±0.02; 93.84±0.01 %; -17.0±0.12 mV respectively. The in vitro release investigation revealed that approximately 70% of Donepezil-HCl was cumulatively released after 24 hours. TEM analysis proved that spherical and smooth particles were obtained and formulations had no toxic effect on cells. The final optimized formulation could be a candidate for Donepezil-HCl application in Alzheimer's treatment with reduced side effects and doses for patients

In Situ Hydrogel Formulation for Intra-Articular Application of Diclofenac Sodium-Loaded Polymeric Nanoparticles.

OBJECTIVES: The world's population is getting older and the number of people suffering from arthritis is a major problem according to World Health Organization's data. In this respect, the need for more efficient treatment for arthritis becomes an urgent issue. In this research, nanoparticle bearing in situ gelling hydrogel formulation was developed for prolonged local delivery of diclofenac sodium (DS). MATERIALS AND METHODS: Emulsion-solvent evaporation technique was used for the preparation of nanoparticles. Particle size, encapsulation efficiency, morphology, and drug release profile of DS loaded biodegradable nanoparticles as well as gel viscosity and gelation time of in situ gelling hydrogel formulations were optimized to increase the time interval between each dose application for enhanced patience compliance. RESULTS: The spherical nanoparticles with a mean particle diameter of 168 nm was obtained and confirmed by both transmission electron microscope and atomic force microscope. Different types of surfactants were tested in the first emulsification step of nanoparticle production process and Arlacel®-C significantly increased the encapsulation efficiency to 89.7%. Thirty days prolonged in vitro release of DS was achieved by using the combined formulation of polymeric nanoparticles and in situ hydrogel prepared by using poloxomer 407 and chitosan. CONCLUSION: Local administration of DS with this novel delivery system could be considered of having potential to minimize side effects associated with decreased amount of drug in dosage form compared to conventional oral dose.