Development of a Novel Histatin-5 Mucoadhesive Gel for the Treatment of Oral Mucositis: In Vitro Characterization and In Vivo Evaluation.

Antimicrobial peptides have appeared to be promising candidates for therapeutic purposes due to their broad antimicrobial activity and non-toxicity. Histatin-5 (Hst-5) is a notable salivary antimicrobial peptide that exhibited therapeutic properties in the oral cavity. Oral mucositis is an acute inflammation of the oral cavity, following cancer therapy. The current treatment methods of oral mucositis have low effectiveness. The aim of this study was to design, formulate and characterize a mucoadhesive gel delivery system for Hst-5 usage in the treatment of oral mucositis. Carbopol 934 and hydroxypropyl methylcellulose (HPMC) have been used in the development of a Hst-5 mucoadhesive gel that was optimized by using Box-Behnken design. The optimized formulation was evaluated in-vitro, based on mucoadhesive strength, viscoelasticity, spreadability, release rate, peptide secondary structure analysis, antimicrobial activity, and storage stability. The efficacy of Hst-5 gel was assessed in vivo in a chemotherapy-induced mucositis model. The results showed a sustained release of Hst-5 from the new formulation. Hst-5 gel exerted antimicrobial activity against Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and Candida albicans. The histopathological, immunohistochemical and statistical analysis showed that the Hst-5 gel had wound healing activity in vivo. The findings of this study indicate that the mentioned compound possesses promising potential as a novel and efficient therapeutic agent in managing oral mucositis. Moreover, the results suggest that the compound is commercially feasible for further development and utilization.

Improvement of memory deficits in the rat model of Alzheimer's disease by erythropoietin-loaded solid lipid nanoparticles.

Erythropoietin (EPO), a hematopoietic factor, is one of the promising neuroprotective candidates in neurodegenerative disorders such as Alzheimer's disease (AD). Due to the high molecular weight, hydrophilicity and rapid clearance from circulation, EPO could not completely pass the blood-brain barrier in the case of systemic administration. To overcome this limitation, EPO-loaded Solid Lipid Nanoparticle (EPO-SLN) was developed in this study using a double emulsion solvent evaporation method (W1/O/W2). Glycerin monostearate (GMS), span®80/span®60, Dichloromethane (DCM) and tween®80 were chosen as lipid, internal phase surfactants, solvent, and external aqueous phase surfactant, respectively. After physicochemical evaluations, the effect of EPO-SLN on the beta-amyloid-induced AD-like animal model was investigated. In vivo evaluations, it was demonstrated that the memory was significantly restored in cognitive deficit rats treated with EPO-SLN compared to the rats treated with native drug using the Morris water maze test. In addition, EPO-SLN reduced the oxidative stress, ADP/ATP ratio, and beta-amyloid plaque deposition in the hippocampus more effectively than the free EPO. Hence, the designed SLN can be regarded as a promising system for safe and effective delivery of EPO in the AD.

Respiratory Administration of Infliximab Dry Powder for Local Suppression of Inflammation.

The airways are verified as a relevant route to improve antibody therapeutic index with superior lung concentration but limited passage into systemic blood stream. The current research aimed to process spray-dried (SD) powder of Infliximab to assess the feasibility of respiratory delivery of antibody for local suppression of lung-secreted tumor necrosis factor α (TNFα). Molecular and structural stability of powders were determined through size exclusion chromatography (SEC-HPLC) and Fourier transform infrared (FTIR) spectroscopy. Particle properties were characterized by laser light scattering, twin stage impinger (TSI), and scanning electron microscopy (SEM). In vitro biological activity was quantified applying L-929 cell line. Ovalbumin (OVA)-challenged balb/c mice were employed to evaluate the anti-TNFα activity of antibody formulation as in vivo experimental model. SD sample consisting of 36 mg trehalose, 12 mg cysteine, and 0.05% of Tween 20 was selected with minimum aggregation/fragmentation rate constants of 0.07 and 0.05 (1/month) based on 1 and 2 months of storage at 40°C and relative humidity of 75%. Fine particle fraction (FPF) value of this formulation was 67.75% with desired particle size and surface morphology for respiratory delivery. EC50 was 8.176 and 6.733 ng/ml for SD Infliximab and Remicade®, respectively. SD antibody reduced TNFα (26.56 pg/ml) secretion in mouse lung tissue, more than 2 orders of magnitudes comparing positive control group (TNFα, 68.34 pg/ml). The success of antibody inhalation mainly depended on the spray drying condition, formulation components, and stability of antibody within aerosolization. Inhaled Infliximab could be a potential drug for local inhibition of lung inflammation.

Doxorubicin and Anti-PD-L1 Antibody Conjugated Gold Nanoparticles for Colorectal Cancer Photochemotherapy.

Colorectal cancer (CRC) is the third leading cause of cancer-related death worldwide. The prognosis and overall survival of CRC are known to be significantly correlated with the overexpression of PD-L1. Since combination therapies can significantly improve therapeutic efficacy, we constructed doxorubicin (DOX) conjugated and anti-PD-L1 targeting gold nanoparticles (PD-L1-AuNP-DOX) for the targeted chemo-photothermal therapy of CRC. DOX and anti-PD-L1 antibody were conjugated to the α-terminal end group of lipoic acid polyethylene glycol N-hydroxysuccinimide (LA-PEG-NHS) using an amide linkage, and PD-L1-AuNP-DOX was constructed by linking LA-PEG-DOX, LA-PEG-PD-L1, and a short PEG chain on the surface of AuNP using thiol-Au covalent bonds. Physicochemical characterizations and biological studies of PD-L1-AuNP-DOX were performed in the presence of near-infrared (NIR) irradiation (biologic studies were conducted using cellular uptake, apoptosis, and cell cycle assays in CT-26 cells). PD-L1-AuNP-DOX (40.0 ± 3.1 nm) was successfully constructed and facilitated the efficient intracellular uptake of DOX as evidenced by pronounced apoptotic effects (66.0%) in CT-26 cells. PD-L1-AuNP-DOX treatment plus NIR irradiation significantly and synergistically suppressed the in vitro proliferation of CT-26 cells by increasing apoptosis and cell cycle arrest. The study demonstrates that PD-L1-AuNP-DOX in combination with synergistic targeted chemo-photothermal therapy has a considerable potential for the treatment of localized CRC.

Effect of amino acids on the stability of spray freeze-dried immunoglobulin G in sugar-based matrices.

The purpose of this study was to prepare spray freeze-dried particles of immunoglobulin G (IgG) using various combinations of trehalose and different amino acids (leucine, phenylalanine, arginine, cysteine, and glycine), and investigate the effect of the amino acids on the stability of IgG during the spray freeze-drying (SFD) process and storage. The morphology and structural integrity of the processed particles were evaluated by physical and spectroscopic techniques. SFD-processed IgG without any excipient resulted in the formation of aggregates corresponding to approximately 14% of IgG. In contrast, IgG formulations stabilized using an optimal level of leucine, phenylalanine, or glycine in the presence of trehalose displayed aggregates <2.2%. In particular, phenylalanine combined with trehalose was most effective in stabilizing IgG against shear, freezing, and dehydration stresses during SFD. Arginine and cysteine were destabilizers displaying aggregation and fragmentation of IgG, respectively. Aggregation and fragmentation were evaluated by dynamic light scattering, ultraviolet spectrophotometry, size-exclusion chromatography, and microchip capillary gel electrophoresis. The IgG formulations prepared with leucine, phenylalanine, or glycine in the presence of trehalose showed good stability after storage at 40 °C and 75% relative humidity for 2 months. Thus, a combination of the excipients trehalose and uncharged, nonpolar amino acids appears effective for production of stable SFD IgG formulations.

Optimization and characterization of spray-dried IgG formulations: a design of experiment approach.

BACKGROUND: The purpose of the present study is to optimize a spray-dried formulation as a model antibody regarding stability and aerodynamic property for further aerosol therapy of this group of macromolecules. METHOD: A three-factor, three-level, Box-Behnken design was employed milligrams of Cysteine (X1), Trehalose (X2), and Tween 20 (X3) as independent variables. The dependent variables were quantified and the optimized formulation was prepared accordingly. SEC-HPLC and FTIR-spectroscopy were conducted to evaluate the molecular and structural status of spray-dried preparations. Particle characterization of optimized sample was performed with the aid of DSC, SEM, and TSI examinations. RESULTS: Experimental responses of a total of 17 formulations resulted in yield values, (Y1), ranging from 21.1 ± 0.2 to 40.2 ± 0.1 (%); beta-sheet content, (Y2), from 66.22 ± 0.19 to 73.78 ± 0.26 (%); amount of aggregation following process, (Y3), ranging from 0.11 ± 0.03 to 0.95 ± 0.03 (%); and amount of aggregation upon storage, (Y4), from 0.81 ± 0.01 to 3.13 ± 0.64 (%) as dependent variables. Results-except for those of the beta sheet content-were fitted to quadratic models describing the inherent relationship between main factors. CONCLUSION: Co-application of Cysteine and Tween 20 preserved antibody molecules from molecular degradation and improved immediate and accelerated stability of spry-dried antibodies. Validation of the optimization study indicated high degree of prognostic ability of response surface methodology in preparation of stable spray-dried IgG. Graphical abstract Spray drying of IgG in the presence of Trehalose, Cysteine and Tween 20.

Effect of molecular weight and ratio of poly ethylene glycols' derivatives in combination with trehalose on stability of freeze-dried IgG.

The influence of poly ethylene glycol (PEG) at different molecular weights (MWs) and ratios was studied on the stability of freeze-dried immune globulin G (IgG). PEGs (600-4000 Dalton) at concentrations of 0.5 and 5% W/V were applied in the presence of 40 and 60% W/W of trehalose to prepare freeze-dried IgG formulations. Size-exclusion chromatography, infra-red spectroscopy, differential scanning calorimeter, and gel electrophoresis were performed to characterize lyophilized samples. Pure IgG demonstrated the highest aggregation of 5.77 ± 0.10% after process and 12.66 ± 0.50% as well as 44.69 ± 0.50% upon 1 and 2 months of storage at 45 °C, respectively. 5% W/V of PEGs 4000 in combination with 40% W/W trehalose, significantly suppressed aggregation, 0.05 ± 0.01%, with minimum aggregation rate constant of 0.32 (1/month). The integrity of IgG molecules and secondary conformation were properly preserved in all formulations comparing native IgG. It could be concluded that appropriate concentration and MW of PEGs, prominently augmented stabilizing effect of trehalose on freeze-dried antibody through inserting additional supportive mechanisms of actions.

The use of amino acids to prepare physically and conformationally stable spray-dried IgG with enhanced aerosol performance.

This study investigated the effect of various amino acids on the molecular and thermodynamic stability of IgG (immune globulin G) as well as its aerosol performance. The antibody was spray-dried in the presence of different amino acids (leucine, phenylalanine, cysteine, glycine, lysine and arginine) using 20% and 50% (w/w) amino acid. SEC-HPLC, SDS-PAGE and IR-spectroscopy were performed to evaluate the stability of spray-dried IgG. The in-vitro aerosol performance of the well-stabilized formulations was subsequently assessed. IgG containing phenylalanine at 20 and 50% w/w produced the lowest content of aggregated antibody (1.35 ± 0.24%) and (1.12 ± 0.15%). The application of phenylalanine and cysteine at 50% (w/w) demonstrated the best storage stability (2 month at 45°C) with a rate constant of 0.006/month and enhanced fine particle fractions of 62.43 ± 0.34% and 70.51 ± 0.23%, respectively. Samples containing 50% arginine exhibited significantly perturbed conformation and, consequently, the highest aggregation rate constant of 0.019/month following storage. These results indicate that phenylalanine and cysteine serve as efficacious amino acids for the preparation of IgG dry powder with regard to stability and aerodynamic properties.

The effective encapsulation of a hydrophobic lipid-insoluble drug in solid lipid nanoparticles using a modified double emulsion solvent evaporation method.

Raloxifene HCl (RH), a selective estrogen receptor modulator (SERM), is indicated for the prophylaxis or treatment of postmenopausal osteoporosis. RH shows extremely poor bioavailability due to limited solubility and an extensive intestinal/hepatic first-pass metabolism. Solid lipid nanoparticles (SLNs) are valuable carriers that can enhance drug bioavailability. However, in the case of RH, the encapsulation of the drug in SLNs remains a challenge because of its poor solubility in both water and lipids. In this study, a series of RH-containing SLNs (RH-SLNs) were generated using a modified double emulsion solvent evaporation (DESE) method. Briefly, RH with various drug/lipid ratios was solubilized in the inner core of a double emulsion using different water/organic solvent mixtures. Our best formulation was achieved with the formation of negatively charged nanoparticles, 180nm in diameter, with an encapsulation and loading efficiency of 85% and 4.5%, respectively. It also showed a Fickian mechanism of the drug release in the basic dissolution media. Thermal analysis revealed a distinct decrease in the crystallinity of lipids and RH in comparison with the unprocessed materials. The results of a cell viability assay also showed a better antiproliferative effect of the drug-loaded SLNs versus the free drug solution. Thus, these results indicated that the modified DESE method could be proposed for the effective encapsulation of RH in SLNs with appropriate physicochemical and biological properties.

C-terminal domain deletion enhances the protective activity of cpa/cpb loaded solid lipid nanoparticles against Leishmania major in BALB/c mice.

BACKGROUND: We have demonstrated that vaccination with pDNA encoding cysteine proteinase Type II (CPA) and Type I (CPB) with its unusual C-terminal extension (CTE) can partially protect BALB/c mice against cutaneous leishmanial infection. Unfortunately, this protection is insufficient to completely control infection without booster injection. Furthermore, in developing vaccines for leishmaniasis, it is necessary to consider a proper adjuvant and/or delivery system to promote an antigen specific immune response. Solid lipid nanoparticles have found their way in drug delivery system development against intracellular infections and cancer, but not Leishmania DNA vaccination. Therefore, undefined effect of cationic solid lipid nanoparticles (cSLN) as an adjuvant in enhancing the immune response toward leishmanial antigens led us to refocus our vaccine development projects. METHODOLOGY/PRINCIPAL FINDINGS: Three pDNAs encoding L. major cysteine proteinase type I and II (with or without CTE) were formulated by cSLN. BALB/c mice were immunized twice by 3-week interval, with cSLN-pcDNA-cpa/b, pcDNA-cpa/b, cSLN-pcDNA-cpa/b(-CTE), pcDNA-cpa/b(-CTE), cSLN, cSLN-pcDNA and PBS. Mice vaccinated with cSLN-pcDNA-cpa/b(-CTE) showed significantly higher levels of parasite inhibition related to protection with specific Th1 immune response development, compared to other groups. Parasite inhibition was determined by different techniques currently available in exploration vacciation efficacy, i.e., flowcytometry on footpad and lymph node, footpad caliper based measurements and imaging as well as lymph node microtitration assay. Among these techniques, lymph node flowcytometry was found to be the most rapid, sensitive and easily reproducible method for discrimination between the efficacy of vaccination strategies. CONCLUSIONS/SIGNIFICANCE: This report demonstrates cSLN's ability to boost immune response magnitude of cpa/cpb(-CTE) cocktail vaccination against leishmaniasis so that the average parasite inhibition percent could be increased significantly. Hence, cSLNs can be considered as suitable adjuvant and/or delivery systems for designing third generation cocktail vaccines.

Delivery of a cocktail DNA vaccine encoding cysteine proteinases type I, II and III with solid lipid nanoparticles potentiate protective immunity against Leishmania major infection.

Earlier generations of Leishmania vaccines have reached the third-phase of clinical trials, however none of them have shown adequate efficacy due to lack of an appropriate adjuvant. In this study, cationic solid lipid nanoparticles (cSLNs) were used to formulate three pDNAs encoding L. major cysteine proteinase type I (cpa), II (cpb) and III (cpc). BALB/c mice were immunized twice with a 3-week interval, with SLN-pcDNA-cpa/b/c, pcDNA-cpa/b/c, SLN, SLN-pcDNA and PBS. Footpad assessments, parasite burden, cytokine and antibody responses were evaluated. Mice vaccinated with SLN-pcDNA-cpa/b/c significantly (p<0.05) showed higher protection levels with specific Th1 immune response development compared to other groups. This is the first report demonstrating cSLNs as a nanoscale vehicle boosting immune response quality and quantity; in a designable trend. The nanomedical feature of this novel formulation can be applied for wide-spread use in genetic vaccination against leishmaniasis, which is currently managed only through relatively ineffectual therapeutic regimens.

Entrapment of 5-fluorouracil into PLGA matrices using supercritical antisolvent processes.

OBJECTIVES: Two different supercritical antisolvent processes were performed to co-precipitate 5-fluorouracil (5-FU) and poly(lactide-co-glycolide) simultaneously. 5-FU is a hydrophilic antitumor agent, and is more effective when administered at a lower dose for a longer period of time. METHODS: Controlled-release polymeric systems of 5-FU were produced, and morphology, thermal behavior, in-vitro release and cytotoxicity of microparticles were analysed. KEY FINDINGS: Dissolution studies showed that 33% of drug was released in 21 days, which represents a long-lasting profile. To evaluate the efficacy of the released drug on cancer cells, the MTT assay cytotoxicity test was performed using human lung carcinoma A549 cell lines. There was no significant difference between the cell inhibition rates of the released drug and unprocessed 5-FU at the same drug concentration level. IC50 values were 69.12 mg/ml for unprocessed 5-FU and 68.71 mg/ml for the released drug. CONCLUSIONS: Application of supercritical processing for co-precipitation of 5-FU and PLGA provided mild and non-aqueous conditions, so the hydrophilic drug incorporated in the polymer had good stability during the process.

Cationic solid lipid nanoparticles loaded by cysteine proteinase genes as a novel anti-leishmaniasis DNA vaccine delivery system: characterization and in vitro evaluations.

PURPOSE: Leishmaniasis is a major health problem in many tropical and sub-tropical countries and development of a safe and easily-available vaccine has high priority. Although several antigens potentially capable of inducing protective immunity have been studied, in the absence of pharmaceutical industry interest they have remained as fine publications only. Amongst them, Cathepsin L-like cysteine proteinases (CPs) have received considerable attention and type I and II CPs have been used in a heterologous prime-boost vaccination regime for experimental visceral leishmaniasis in dogs. Due to the promising results of the mentioned vaccination regime, we aimed to evaluate cationic solid lipid nanoparticles (cSLNs) for in vitro delivery of cpa, cpb and cpb(CTE) intended to be used as a cocktail DNA vaccine in our forthcoming studies. METHODS: cSLNs were formulated of cetyl palmitate, cholesterol, DOTAP and Tween 80 via melt emulsification method followed by high shear homogenization. Different formulations were prepared by anchoring pDNAs on the surface of cSLNs via charge interaction. The formulations were characterized according to their size and zeta potential as well as pDNA integrity and stability against DNase I treatment. Lipoplexes' cytotoxicity was investigated on COS-7 cells by MTT test. The effect of the DOTAP:pDNA ratio on protection ability and cytotoxicity was also studied. In vitro transfection efficiency was qualified by fluorescent microscopy and quantified using flow cytometry technique. RESULTS: cSLN-pDNA complexes were formulated with suitable size and zeta potential. Efficiency/cytotoxicity ratio of cSLN-pDNAs formulations was comparable to linear PEI-25KD-pDNAs polyplexes while exhibiting significantly lower cytotoxicity. CONCLUSION: Tested formulations were able to deliver immunogenic CP genes efficiently. This data proves the ability of this system as a promising DNA vaccine carrier for leishmaniasis to cover the main drawback of naked pDNA delivery that is rapid elimination from the circulation.

Preparation of 5-fluorouracil nanoparticles by supercritical antisolvents for pulmonary delivery.

This study concerns the supercritical antisolvent process which allows single-step production of 5-fluorouracil (5-FU) nanoparticles. This process enhances the physical characteristics of 5-FU in order to deliver it directly to the respiratory tract. Several mixtures of methanol with dichloromethane, acetone, or ethanol were used for particle preparation, and their effects on the physical characteristics of the final products were studied. The conditions of the experiment included pressures of 100 and 150 bar, temperature of 40°C, and a flow rate of 1 mL/min. The particles were characterized physicochemically before and after the process for their morphology and crystallinity. In spite of differences in size, the particles were not very different regarding their morphology. The resulting particles were of a regular shape, partly spherical, and appeared to have a smooth surface, whereas the mechanically milled particles showed less uniformity, had surface irregularities and a high particle size distribution, and seemed aggregated. Particles of 5-FU precipitated from methanol-dichloromethane 50:50 had a mean particle size of 248 nm. In order to evaluate the aerodynamic behavior of the nanoparticles, six 5-FU dry powder formulations containing mixtures of coarse and fine lactose of different percentages were prepared. Deposition of 5-FU was measured using a twin-stage liquid impinger and analyzed using a validated high pressure liquid chromatography method. Addition of fine lactose improved the aerodynamic performance of the drug, as determined by the fine particle fraction.

Extraction and preconcentration of salbutamol and terbutaline from aqueous samples using hollow fiber supported liquid membrane containing anionic carrier.

This paper presents a new three-phase liquid-phase microextraction (LPME) strategy for extraction and preconcentration of salbutamol (SB) and terbutaline (TB) from aqueous samples, including urine. The drugs were extracted from 11 ml of aqueous sample (source phase; SP) into an organic phase with microliter volume located inside the pores of a polypropylene hollow fiber, and then back-extracted into 24 microl of a second aqueous solution as the receiving phase (RP), located in the lumen of the hollow fiber. In preliminary experiments, we tried to transport the drugs using a pH gradient between the two sides of the hollow fiber. Due to the existence of both amine and phenolic groups on the drugs, very little transport occurred and enrichment factors (EF) less than one were obtained. Further experiments were done in the presence of bis(2-ethylhexyl) monohydrogenphosphoric acid (D2EHPA) or methyltrioctylammonium chloride (Aliquat 336) in the organic phase, to extract drugs from acidic and basic matrices, respectively. Results showed that transport of drugs from alkaline solution into 1M of sodium bromide occurred when the membrane was impregnated with dihexyl ether containing 20% Aliquat 336. To optimize the EF, the effects of different parameters such as the nature of organic solvent used to impregnate the membrane, compositions and volumes of SP and RP, type and concentration of carrier, extraction time and stirring rate were investigated. Optimal results were obtained in the presence of 0.005 M of NaOH (pH 11.70) in the SP, 1M of NaBr in the RP, 20% of Aliquat 336 in dihexyl ether as membrane impregnation solvent, stirring rate of 500 rpm and extraction time of 60 min. Under these conditions, enrichment factors of 52.9 and 213.1, dynamic linear ranges of 20-5000 and 10-5000, and limits of detection of 2.5 and 0.5 ng/ml were obtained for salbutamol and terbutaline, respectively. Also determination of drugs in environmental water and urine samples in the range of nanograms per millilitre with RSDs<10% was possible using HPLC-photodiode array detection or HPLC-MS.