PEG-PCL Nanocapsules Containing Curcumin: Validation of HPLC Method for Analyzing Drug-loading Efficiency, Stability Testing and Cytotoxicity on NIH-3T3 Cell Line

Abstract Curcumin (CUR) shows potential use for treating cancer. However, CUR has low solubility and reduced bioavailability, which limit its clinical effect. Therefore, the development of nanocarriers can overcome these problems and can ensure the desired pharmacological effect. In addition, it is mandatory to prove the quality, the efficacy, and the safety for a novel nanomedicine to be approved. In that sense, this paper aimed (a) to prepare CUR-loaded polyethylene glycol-poly(ε-caprolactone) nanocapsules; (b) to validate an analytical method by high performance liquid chromatography (HPLC) for quantifying CUR in these nanoformulations; (c) to evaluate the physicochemical stability of these formulations; and to investigate their cytotoxicity on NIH-3T3 mouse fibroblast cells. The HPLC method was specific to CUR in the loaded nanocapsules, linear (r = 0.9994) in a range of 10.0 to 90.0 µg.mL-1 with limits of detection and quantification of 0.160 and 0.480 µg.mL-1, respectively. Precision was demonstrated by a relative standard deviation lower than 5%. Suitable accuracy (102.37 ± 0.92%) was obtained. Values of pH, particle size, polydispersity index, and zeta potential presented no statistical difference (p > 0.05) for CUR-loaded nanoparticles. No cytotoxicity was observed against NIH-3T3 mouse embryo fibroblast cell line using both the tetrazolium salt and sulforhodamine B assays. In conclusion, a simple and inexpensive HPLC method was validated for the CUR quantification in the suspensions of nanocapsules. The obtained polymeric nanocapsules containing CUR showed suitable results for all the performed assays and can be further investigated as a feasible novel approach for cancer treatment.

Transplantation of retinoic acid treated murine embryonic stem cells & behavioural deficit in Parkinsonian rats.

Background & objectives: Stem cell therapy has been considered as an ideal option for the treatment of Parkinson’s disease. Murine embryonic stem cells (mESCs)-derived dopaminergic (DA) neurons may substitute the degenerated neurons in the brain. In this study we generated highly enriched cultures of neural progenitors from mESCs and grafted them into the striatum of Parkinsonian rats to evaluate their ability to improve impaired function. Methods: An animal model was developed for Parkinson’s disease in rats, using 6- hydroxy dopamine. The animals were divided into two groups: (i) the control group treated with culture medium only, and (ii) the experimental group, which was treated with a murine ESC cell-line (CCE). Transplanted cells were labelled with bromodeoxyuridine (BrdU), exposed to retinoic acid and then engrafted within the striatum of the rat model. Results: Treated ES cells by retinoic acid were found to relieve apomorphine-induced asymmetric motor behaviour. Immunohistochemistry results revealed tyrosine hydroxlase immunoreactivity in engrafted cells 15 days after transplantation. Further, the ultrastructural examination along with cresyl violet staining confirmed that the cells gained neuronal and glial appearance. Interpretation & conclusions: Our data demonstrate that retinoic acid treatment and transplanting ESC cells to the lessioned brain can lead to the generation of putative dopaminergic neurons and functional recovery in parkinsonian rat model with.

Effects of different doses of bone morphogenetic protein 4 on viability and proliferation rates of mouse embryonic stem cells

In this study, we examined the effect of different doses of bone morphogenetic protein 4 [BMP4] on CCE mouse embryonic stem cells [ESCs] viability and proliferation rates in order to improve the outcome of induction processes and make a system with highest viability and proliferation rates for further studies on BMP4 roles in multiple developmental stages. Expression of Oct-4 was studied and confirmed in this cell line immunocytochemically. Also, in order to evaluate the proliferation and viability rates in BMP4-treated cells, ESCs were cultured in Dulbecco's Modified Eagle Medium [DMEM] containing different doses of BMP4 [0, 0.01, 0.1, 1, 5, 25, 50 and 100ng/ml]. The mean number of whole cells and living cells were considered as proliferation and survival rates respectively. Data analysis was done with ANOVA test. The results showed that there were significant differences between the mean percent of viability between 1ng/ml and 0 ng/ml [control] and 50 and 100 ng/ml BMP4 [p