Mesoporous silica nanoparticles enhance the cytotoxicity of curcumin

Curcumin encapsulated in mesoporous silica nanoparticles showed improved solubility, in vitro release profile and significantly enhanced cell cytotoxicity compared to the pure drug

Nanodispersed UV blockers in skin-friendly silica vesicles with superior UV-attenuating efficiency

Using a pig ear skin model, it is demonstrated that silica vesicles show higher skin safety compared to dense silica nanoparticles with similar sizes. A hydrophobic UV blocker is efficiently dispersed in silica vesicles in an amorphous state, leading to ultrahigh UV-attenuating efficiency and a sun protection factor of 100 in a sunscreen formulation

Modulating in vitro release and solubility of griseofulvin using functionalized mesoporous silica nanoparticles

Mesoporous silica nanoparticles (MCM-41) were used as a carrier system to study the influence of surface charge and hydrophobicity on solubility and in-vitro drug release behavior of Griseofulvin, a potent antifungal drug with low water solubility. Bare MCM-41 with a pure silica composition, MCM-41 after amino functionalization (MCM-41-NH2) and methyl functionalization (MCM-41-CH3) were used in this study followed by encapsulation of griseofulvin. Various characterization techniques have been employed to confirm the successful drug loading inside the nanopores. The surface functionalization on MCM-41 is found to have significant effect on griseofulvin's in vitro release and solubility. Both negatively and positively charged surface showed enhancement in solubility and drug release of griseofulvin. However, the hydrophobic modification led to a retarded drug release, which is caused by the poor wetting effect in the case of MCM-41-CH3 nanoparticles. (C) 2014 Elsevier Inc. All rights reserved

One-pot synthesis of pH-responsive Eudragit-mesoporous silica nanocomposites enable colonic delivery of glucocorticoids for the treatment of inflammatory bowel disease

Oral glucocorticoids are backbones for the acute management of inflammatory bowel disease (IBD). However, the clinical effectiveness of conventional oral dosage forms of glucocorticoids is hindered by their low delivery efficiency and systemic side effects. To overcome this problem, a smart drug delivery system with high loading capacity and colonic release by coating functionalized mesoporous silica nanoparticles (MSNs) with a pH‐responsive polymer Eudragit S100 is proposed. In vitro dissolution tests show that Eudragit‐coated MSNs can limit the burst release of loaded prednisolone and budesonide in the gastric environment with more than 60% of the drugs released only at colonic pH (i.e., pH ≥ 7). In vivo therapeutic efficacy of budesonide‐loaded nanoparticles is tested in a murine model of dextran sodium sulfate‐induced colitis. An oral budesonide dose of 0.2 mg kg−1 nanoparticles with Eudragit coating improves the disease activity index compared to other groups. Interestingly, both coated and uncoated nanoparticles show pathological improvements demonstrated by similar levels of histological colitis score. However, coated nanoparticles significantly decrease mRNA expression of the cytokines (Il‐1β, Il‐17, and Il‐10) particularly in proximal colon, indicating colonic delivery. Overall, this study demonstrates the effectiveness of a simple method to fabricate targeted nanomedicine for the treatment of IBD.Peer reviewe

Formulation technologies and advances for oral delivery of novel nitroimidazoles and antimicrobial peptides

Antibiotic resistance has become a global crisis, driving the exploration for novel antibiotics and novel treatment approaches. Among these research efforts two classes of antibiotics, bicyclic nitroimidazoles and antimicrobial peptides, have recently shown promise as novel antimicrobial agents with the possibility to treat multi-drug resistant infections. However, they suffer from the issue of poor oral bioavailability due to disparate factors: low solubility in the case of nitroimidazoles (BCS class II drugs), and low permeability in the case of peptides (BCS class III drugs). Moreover, antimicrobial peptides present another challenge as they are susceptible to chemical and enzymatic degradation, which can present an additional pharmacokinetic hurdle for their oral bioavailability. Formulation technologies offer a potential means for improving the oral bioavailability of poorly permeable and poorly soluble drugs, but there are still drawbacks and limitations associated with this approach. This review discusses in depth the challenges associated with oral delivery of nitroimidazoles and antimicrobial peptides and the formulation technologies that have been used to overcome these problems, including an assessment of the drawbacks and limitations associated with the technologies that have been applied. Furthermore, the potential for supercritical fluid technology to overcome the shortcomings associated with conventional drug formulation methods is reviewed

Luminescent porous silicon nanoparticles for continuous wave and time-gated photoluminescence imaging

Luminescent porous silicon nanoparticles (LpSiNPs) display red-orange photoluminescence (PL) that provides large penetration depth for precise deep-tissue imaging and diagnostics. Herein, we describe in detail the fabrication process of porous silicon nanoparticles (pSiNPs), activation of photoluminescence, quantum yield measurement, and PL imaging. LpSiNPs perform as imaging probe for both the continuous wave and time-gated PL imaging

Curcumin-cyclodextrin encapsulated chitosan nanoconjugates with enhanced solubility and cell cytotoxicity

Curcumin (CUR), a naturally derived anti-cancer cocktail is arguably the most widely studied neutraceutical. Despite a lot of promises, it is yet to reach the market as an active anti-cancer formulation. In the present study, we have prepared highly soluble (3. mg/ml) CUR-γ-hydroxypropyl cyclodextrin (CUR-CD) hollow spheres. CUR-CD hollow spheres were prepared by a novel and scalable spray drying method. CUR-CD was then encapsulated into positively charged biodegradable chitosan (CUR-CD-CS) nanoparticles. The CUR-CD-CS nanoparticles were characterised by TEM, SEM, DLS, drug loading and in vitro release. We tested the efficacy of these CUR-CD-CS nanoparticles in SCC25 cell lines using MTT assay and investigated its cellular uptake mechanism. We also studied Oligo DNA loading in CUR-CD-CS nanoparticles and its delivery via confocal imaging and FACS analysis. Our results demonstrated that CUR-CD-CS nanoparticles showed superior in vitro release performance and higher cytotoxicity in SCC25 cell line amongst all tested formulations. The cytotoxicity results were corroborated by cell cycle analysis and apoptosis test, showing nearly 100% apoptotic cell death in the case of CUR-CD-CS nanoparticles. Compared to CS nanoparticles, CS-CD nanoformulation showed higher cellular delivery of Cy3-Oligo DNA which was tested quantitatively using flowcytometry analysis, indicating that CD not only enhanced CUR solubility but also boosted the cellular uptake. Our study shows that rationally designed bio-degradable natural biomaterials have great potential as next generation nano-carriers for hydrophobic drug delivery such as CUR with potential of dual drug-gene delivery

An overview of recent patents on nanosuspension

Pharmaceutical scientists involved in drug discovery and drug development are facing serious problems with newer poorly water soluble drugs with respect to their dissolution and bioavailability. Reducing the particle size of active pharmaceutical ingredient has been an efficient and reliable method for improving the bioavailability of insoluble drugs. Nanosuspension has emerged as an efficient and promising strategy for delivery of insoluble drugs due to its unique advantages such as ease of modification, process flexibility, targeting capabilities, altered pharmacokinetic profile leading to safety and efficacy. These unique features of nanosuspension have enabled its use in various dosage forms, including specialized delivery systems such as oral, parenteral, peroral, ocular and pulmonary routes. Currently, efforts are being directed to extend their applications in site-specific drug delivery. Large numbers of products based on nanosuspension are in the market and few are under clinical trials. The commercialization potential of nanosuspension based formulation for oral route is well established and products for other routes will enter the market within short span. Among the various techniques available, only wet milling technique has been successfully used for commercial production of nanosuspension. Nanosuspension based patents have extensive potential of reaching faster in the market as compared to other nanotechnology based formulations. This review covers various aspects of techniques of preparation, route of administration and commercialization of nanosuspension with main focus on the recent patents granted in the field

Virus-like Silica Nanoparticles Improve Permeability of Macromolecules across the Blood–Brain Barrier In Vitro

The presence of the blood–brain barrier (BBB) limits the delivery of therapies into the brain. There has been significant interest in overcoming the BBB for the effective delivery of therapies to the brain. Inorganic nanomaterials, especially silica nanoparticles with varying surface chemistry and surface topology, have been recently used as permeation enhancers for oral protein delivery. In this context, nanoparticles with varying sizes and surface chemistries have been employed to overcome this barrier; however, there is no report examining the effect of nanoscale roughness on BBB permeability. This paper reports the influence of nanoscale surface roughness on the integrity and permeability of the BBB in vitro, using smooth surface Stöber silica nanoparticles (60 nm) compared to rough surface virus-like silica nanoparticles (VSNP, 60 nm). Our findings reveal that VSNP (1 mg/mL) with virus-mimicking-topology spiky surface have a greater effect on transiently opening endothelial tight junctions of the BBB than the same dose of Stöber silica nanoparticles (1 mg/mL) by increasing the FITC-Dextran (70 kDa) permeability 1.9-fold and by decreasing the trans-endothelial electrical resistance (TEER) by 2.7-fold. This proof-of-concept research paves the way for future studies to develop next-generation tailored surface-modified silica nanoparticles, enabling safe and efficient macromolecule transport across the BBB