Nano-curcumin safely prevents streptozotocin-induced inflammation and apoptosis in pancreatic beta cells for effective management of Type 1 diabetes mellitus.

BACKGROUND AND PURPOSE: Approaches to prevent selective and progressive loss of insulin-producing beta cells in Type 1 diabetes mellitus (T1DM) will help to manage this prevalent and devastating disease. Curcumin (CUR), a natural anti-inflammatory substance, suppresses diabetes-associated inflammation and cell death. However, very high doses need to be used because of poor oral bioavailability, making it difficult to translate the anti-inflammatory actions to clinical situations. EXPERIMENTAL APPROACH: We have prepared biodegradable nanosystems encapsulating curcumin (nCUR), resulting in at least nine-fold improvement in oral bioavailability. Here, we tested the ability of nCUR to prevent streptozotocin (STZ)-induced inflammation and apoptosis in pancreatic islets and beta cells, in rats. KEY RESULTS: Non-fasted rats pretreated with 10 or 50 mg·kg-1 nCUR 6 h prior to STZ challenge had up to 37% reduction in the glucose levels, while plain CUR (50 mg·kg-1 ) results in 12% reduction. This treatment with nCUR was accompanied by decreased islet or beta cell death, as shown by TUNEL assay and H&E staining. Both CUR and nCUR significantly decreased levels of inflammatory cytokines in pancreatic tissue homogenates that correlated well with minimal histiocytic infiltration. Pre-treatment with nCUR, but not CUR, decreased 8-oxo-2'-deoxyguanosine, a sensitive biomarker of ROS-induced DNA damage, in pancreas. In normal rodents, daily dosing for 28 days, with nCUR (25-100 mg·kg-1 ) did not cause any deleterious health issues by the carrier. CONCLUSIONS AND IMPLICATIONS: Together, these data indicate a potentially translatable dose of nCUR that is safe and efficacious in improving beta cell function, which could prevent T1DM.

Atomic force microscopy images label-free, drug encapsulated nanoparticles in vivo and detects difference in tissue mechanical properties of treated and untreated: a tip for nanotoxicology.

Overcoming the intractable challenge of imaging of label-free, drug encapsulated nanoparticles in tissues in vivo would directly address associated regulatory concerns over 'nanotoxicology'. Here we demonstrate the utility of Atomic Force Microscopy (AFM) for visualising label-free, drug encapsulated polyester particles of ∼280 nm distributed within tissues following their intravenous or peroral administration to rodents. A surprising phenomenon, in which the tissues' mechanical stiffness was directly measured (also by AFM) and related to the number of embedded nanoparticles, was utilised to generate quantitative data sets for nanoparticles localisation. By coupling the normal determination of a drug's pharmacokinetics/pharmacodynamics with post-sacrifice measurement of nanoparticle localisation and number, we present for the first time an experimental design in which a single in vivo study relates the PK/PD of a nanomedicine to its toxicokinetics.

Towards scale-up and regulatory shelf-stability testing of curcumin encapsulated polyester nanoparticles.

This study reports scale-up and shelf-stability of curcumin encapsulated poly(lactic acid-co-glycolic acid) (PLGA) nanoparticles. The curcumin encapsulated PLGA nanoparticles were prepared by emulsification solvent evaporation/diffusion, and large quantities were made by varying the homogenisation time (5, 15 and 30 min). The particle size decreased as the homogenisation duration increased from 5 to 30 min, and the particles were spherical as confirmed by atomic force microscopy. For the large-scale preparations, the mean particles size was found to be 288.7 ± 3.4 (polydispersity index 0.15 ± 0.01) with curcumin entrapment 52.5 ± 4.3 %, which were comparable to the lab-scale preparations. The curcumin encapsulated nanoparticles were freeze-dried using sucrose (5 %, w/v) as a cryoprotectant. The freeze-dried nanoparticles were subjected to 6-month stability study as per the International Conference on Harmonisation guideline at room temperature and refrigerated storage conditions. Intermediate sampling was done (monthly), and the nanoparticles were thoroughly characterised for particle size, entrapment efficiency, surface morphology and crystallinity, which were compared to fresh preparations. The curcumin encapsulated PLGA nanoparticles were found to be stable at refrigerated as well as room temperature storage test conditions indicated by their particle characteristics. X-ray diffraction results confirm amorphous nature of curcumin on nano-encapsulation that stays intact after freeze drying and 6-month stability testing. Together these data offer possibility of producing large quantities of polymer nanoparticles that are suitable for room as well as refrigerated storage conditions opening up possibilities to conduct repeated dosings in a chronic setting or regulatory toxicology studies of such nanomedicines.

Porphyran capped gold nanoparticles as a novel carrier for delivery of anticancer drug: in vitro cytotoxicity study.

In the present study, we have explored porphyran as a reducing agent for one pot size controlled green synthesis of gold nanoparticles (AuNps) and further investigated its application as a carrier for the delivery of an anticancer drug. The prepared AuNps showed surface plasmon resonance centered at 520 nm with average particle size of 13±5 nm. FTIR spectra suggested that the sulfate moiety is mainly responsible for reduction of chloroauric acid. The capping of the AuNps with porphyran was evident from the negative zeta potential value responsible for the electrostatic stability. Thus, porphyran acts as reducing as well as capping agent. These AuNps are highly stable in a wide range of pH and electrolyte concentration. Porphyran capped AuNps exhibited enhanced cytotoxicity on human glioma cell line (LN-229) as compared to native porphyran. Consequently, these AuNps have been utilized as a carrier for delivery of the anticancer drug doxorubicin hydrochloride (DOX). Spectroscopic examination revealed that DOX conjugated onto AuNps via hydrogen bonding. The release of DOX from DOX loaded AuNps was found to be sixfold higher in acetate buffer (pH 4.5) as compared to physiological buffer (pH 7.4). Further, the DOX loaded AuNps demonstrated higher cytotoxicity on LN-229 cell line as compared with an equal dose of native DOX solution. This established the potential of these AuNps as a carrier for anticancer drug delivery.

Biosynthesis of gold nanoparticles using therapeutic enzyme: in-vitro and in-vivo efficacy study.

The present contribution deals with the synthesis of gold nanoparticles using a therapeutic enzyme serratiopeptidase followed by the in-vitro and in-vivo evaluation to demonstrate the retention of therapeutic activity of the enzyme. Here, gold nanoparticles were synthesized at 25 degrees C and physiological pH 7. The formation of serratiopeptidase reduced gold nanoparticles was confirmed by UV visible spectroscopy, transmission electron microscopy, X-ray diffractometer and fourier transform infrared spectroscopy. Proteolytic enzyme activity assay revealed that the composite contained 64% enzyme capped on AuNps while the remaining 36% enzyme remained in the supernatant. Further, retention of enzymatic activity of these nanoparticles was confirmed by in-vitro casein agar plate method as well as by in-vivo anti-inflammatory activity performed in experimental animals. Six month stability study at ambient temperature (25 degrees C) revealed that gold nanoparticles were stable as indicated by no shift in the surface plasmon band. In conclusion, physiological condition is an important process condition for controlled synthesis of highly stable gold nanoparticle with respect to retention of enzymatic activity. Also use of gold nanoparticles as a carrier for serratiopeptidase led to an improved anti-inflammatory response.

Ternary complexation of carvedilol, beta-cyclodextrin and citric acid for mouth-dissolving tablet formulation.

The purpose of this study was to improve the solubility and dissolution rate of carvedilol by forming a ternary complex with beta-cyclodextrin and citric acid and to formulate its mouth-dissolving tablets. The rationale for preparing mouth-dissolving tablet of carvedilol was to make the drug available in a soluble form in the mouth, which would facilitate its absorption from the buccal cavity. This would help to overcome its first-pass metabolism and thereby improve bioavailability. Phase solubility studies revealed the ability of beta-cyclodextrin and citric acid to complex with carvedilol and significantly increase its solubility. Ternary complexation of carvedilol was carried out with beta-cyclodextrin and citric acid by physical mixing, kneading and spray drying methods and the prepared complexes were characterized by Fourier transform infra red spectroscopy, differential scanning calorimetry, powder X-ray diffractometry, scanning electron microscopy and complexation efficiency. The complex obtained by the spray drying method resulted in highest complexation efficiency and a 110-fold increase in the solubility of carvedilol. The mouth-dissolving tablets formulated using the spray dried complex with suitable excipients showed 100 % dissolution within five minutes. Accelerated stability studies of mouth-dissolving tablets carried out as per ICH guidelines revealed that the tablets were stable.