Design of experiments approach for the development of a validated method to determine the exenatide content in poly(lactide-co-glycolide) microspheres.

Due to the lack of pharmacopeia guidelines for injectable microspheres based on poly (D, L-lactide-co-glycolide) (PLGA), an internal method validation is a critical prerequisite for quality assurance. One of the essential issues of developing peptide-based drugs loaded PLGA microspheres is the precise determination of the amount of peptide drug entrapped in the microspheres. The aim of this study is the development and optimization of a method for measuring the drug content loading of PLGA microspheres using exenatide as a model peptide drug. Exenatide-loaded PLGA microspheres were prepared by a double emulsion solvent evaporation method. The extraction method to determine exenatide content in microspheres was optimized using Design of Experiments (DoE) approach. After the initial screening of six factors, using Fractional Factorial design (FFD), four of them, including type of organic solvent, buffer/organic solvent ratio (v/v), shaking time and pH, exhibited significant effects on the response, namely the exenatide loading, and a Box-Behnken design (BBD) was subsequently applied to obtain its optimum level. The optimum level for organic solvent volume, buffer/organic solvent ratio, shaking time, and pH were 4 ml, 1, 5.6 hrs, and pH 6, respectively. The exenatide content in microspheres under these conditions was 6.4 ± 0.0 (%w/w), whereas a value of 6.1% was predicted by the derived equation. This excellent agreement between the actual and the predicted value demonstrates that the fitted model can thus be used to determine the exenatide content.

PEGylated superparamagnetic iron oxide nanoparticles (SPIONs) ameliorate learning and memory deficit in a rat model of Alzheimer's disease: Potential participation of STIMs.

The amyloid-beta (Aß) fibrillation process seems to execute a principal role in the neuropathology of Alzheimer's disease (AD). Accordingly, novel therapeutic plans have concentrated on the inhibition or degradation of Aß oligomers and fibrils. Biocompatible nanoparticles (NPs), e.g., gold and iron oxide NPs, take a unique capacity in redirecting Aß fibrillation kinetics; nevertheless, their impacts on AD-related memory impairment have not been adequately evaluated in vivo. Here, we examined the effect of commercial PEGylated superparamagnetic iron oxide nanoparticles (SPIONs) on the learning and memory of an AD-animal model. The outcomes demonstrated the dose-dependent effect of SPIONs on Aß fibrillation and learning and memory processes. In vitro and in vivo findings revealed that Low doses of SPIONs inhibited Aß aggregation and ameliorated learning and memory deficit in the AD model, respectively. Enhanced level of hippocampal proteins, including brain-derived neurotrophic factor, BDNF, phosphorylated-cAMP response element-binding protein, p-CREB, and stromal interaction molecules, e.g., STIM1 and STIM2, were also observed. However, at high doses, SPIONs did not improve the detrimental impacts of Aß fibrillation on spatial memory and hippocampal proteins expression. Overall, we revealed the potential capacity of SPIONs on retrieval of behavioral and molecular manifestations of AD in vivo, which needs further investigations to determine the mechanistic effect of SPIONs in the AD conundrum.

Polyurethane/carboxymethylcellulose nanofibers containing Malva sylvestris extract for healing diabetic wounds: Preparation, characterization, in vitro and in vivo studies.

In this study, new polyurethane (PU)-based nanofibers wound dressings containing Malva sylvestris extract were prepared and their effect on diabetic wound healing process was evaluated. Different amounts of carboxymethyl cellulose (CMC) were used to improve the absorption ability of wound exudates. The result showed that the usage of 20% w/w CMC in the polymer blend; and producing of nanofibers with an average diameter of 386.5 nm, led to the gradual release of the herbal compound in 85 h and bead-free morphology. Due to the antibacterial activity of wound dressing and wound healing process, the amount of 15% w/w herbal extract was selected as the optimum. For this sample, the fluid absorption was 412.31%. The extract loaded wound dressing samples showed satisfactory effects on Staphylococcus aureus and Escherichia coli bacteria. In vivo wound-healing and histological performance observations indicated that the use of the herbal extract in wound dressing improved wound healing significantly. On day 14, the average healing rate for gauze bandage, PU/CMC, and different amounts of 5, 10, 15 and 20% w/w extract containing wound dressings was 32.1 ± 0.2%, 51.4 ± 0.4%, 71 ± 0.14%, 87.64 ± 1.02%, 95.05 ± 0.24% and 95.11 ± 0.2%, respectively. Compared to the control groups, treatments with extract loaded wound dressings were effective in lowering acute and chronic inflammations. In diabetic rat wounds, collagen deposition and neovascularization were higher in wounds treated with an herbal extract containing wound dressing compared to the wounds treated with a gauze bandage and PU/CMC treated wounds. It can be suggested that this product may be considered as a good dual anti-inflammatory-antimicrobial wound dressing candidate for improving the diabetic wound healing.

Magnetic bio-metal-organic framework nanocomposites decorated with folic acid conjugated chitosan as a promising biocompatible targeted theranostic system for cancer treatment.

In this work, a multifunctional magnetic Bio-Metal-Organic Framework (Fe3O4@Bio-MOF) coated with folic acid-chitosan conjugate (FC) was successfully prepared for tumor-targeted delivery of curcumin (CUR) and 5-fluorouracil (5-FU) simultaneously. Bio-MOF nanocomposite based on CUR as organic linker and zinc as metal ion was prepared by hydrothermal method in the presence of amine-functionalized Fe3O4 magnetic nanoparticles (Fe3O4@NH2 MNPs). 5-FU was loaded in the magnetic Bio-MOF and the obtained nanocarrier was then coated with FC network. The prepared nanocomposite (NC) was fully characterized by high resolution-transmission electron microscope (HR-TEM), field emission scanning electron microscopy (FE-SEM), Dynamic light scattering (DLS), X-ray diffraction analysis (XRD), thermogravimetric analysis (TGA), vibrating sample magnetometry (VSM), nuclear magnetic resonance (NMR), and UV-vis analyses. In vitro release study showed controlled release of CUR and 5-FU in acidic pH confirming high selectivity and performance of the carrier in cancerous microenvironments. The selective uptake of 5-FU-loaded Fe3O4@Bio-MOF-FC by folate receptor-positive MDA-MB-231 cells was investigated and verified. The ultimate nanocarrier exhibited no significant toxicity, while drug loaded nanocarrier showed selective and higher toxicity against the cancerous cells than normal cells. SDS PAGE was also utilized to determine the protein pattern attached on the surface of the nanocarriers. In vitro and in vivo MRI studies showed negative signal enhancement in tumor confirming the ability of the nanocarrier to be applied as diagnostic agent. Owing to the selective anticancer release and cellular uptake, acceptable blood compatibility as well as suitable T2 MRI contrast performance, the target nanocarrier could be considered as favorable theranostic in breast cancer.

Effect of Glucose on Liposome-Plasma Protein Interactions: Relevance for the Physiological Response of Clinically Approved Liposomal Formulations.

Recently, the concept is emerging that the reduced success of nanoparticles in clinical practice is due to the adsorption of the "biomolecular corona (BC)," which alters their biological identity. Apart from protein variations, alterations in the human metabolome may change the BC decoration, which has poorly been addressed so far. Here, glucose is used as a model metabolite and how the interactions between liposomes (as a model nanoparticle) and plasma proteins are influenced by normal and diabetic sugar blood levels is explored. As model liposomes, Doxoves and Onivyde are used that are used for the treatment of breast and metastatic pancreatic cancer, respectively. It is shown that glucose does affect the structure and composition of BC. The biological effects of liposome-BC complexes are investigated in MCF 7 and MDA-MB-231 breast cancer cells for Doxoves and in pancreatic adenocarcinoma (PANC-1) and insulinoma (INS-1) cells for Onivyde. In the presence of glucose, the cellular toxicity of liposome-protein complexes and uptake by human monocytic THP1 cell line increases. These results demonstrate that alterations in glucose concentration, and more generally changes in the human metabolome, may play a fundamental role in the biological identity of liposomes and, consequently, on their in vivo physiological readouts including therapeutic efficacy.

A novel nanoemulsion-based method to produce ultrasmall, water-dispersible nanoparticles from chitosan, surface modified with cell-penetrating peptide for oral delivery of proteins and peptides.

A simple and reproducible water-in-oil (W/O) nanoemulsion technique for making ultrasmall (<15 nm), monodispersed and water-dispersible nanoparticles (NPs) from chitosan (CS) is reported. The nano-sized (50 nm) water pools of the W/O nanoemulsion serve as "nano-containers and nano-reactors". The entrapped polymer chains of CS inside these "nano-reactors" are covalently cross-linked with the chains of polyethylene glycol (PEG), leading to rigidification and formation of NPs. These NPs possess excessive swelling properties in aqueous medium and preserve integrity in all pH ranges due to chemical cross-linking with PEG. A potent and newly developed cell-penetrating peptide (CPP) is further chemically conjugated to the surface of the NPs, leading to development of a novel peptide-conjugated derivative of CS with profound tight-junction opening properties. The CPP-conjugated NPs can easily be loaded with almost all kinds of proteins, peptides and nucleotides for oral delivery applications. Feasibility of this nanoparticulate system for oral delivery of a model peptide (insulin) is investigated in Caco-2 cell line. The cell culture results for translocation of insulin across the cell monolayer are very promising (15%-19% increase), and animal studies are actively under progress and will be published separately.