Ronny Martien

Thiolated hydroxyethyl cellulose: design and in vitro evaluation of mucoadhesive and permeation enhancing nanoparticles.

Within this study, HEC-cysteamine nanoparticles with free thiol groups in the range of 117-1548 μmol/g were designed and characterized. Nanoparticles were generated via ionic gelation of the cationic polymer with tripolyphosphate (TPP) followed by covalent crosslinking via disulfide bond formation using H2O2 as oxidant. The mean diameter of the particles was in the range of 270-360 nm, and zeta potential was determined to be +4 to +10 mV. Nanoparticles were evaluated in terms of mucoadhesive, permeation enhancing, and biocompatible properties as well as biodegradability. The particles remained attached to porcine intestinal mucosa up to 70% after 3h of incubation. The more nanoparticles were oxidized; however, the less were their mucoadhesive properties. Nanoparticles applied in a concentration of 0.5% (m/v) with the highest content of free thiol groups improved the transport of fluorescein isothiocyanate dextran 4 (FD4) across Caco-2 cell monolayer 3.94-fold in comparison with control (buffer). In addition, the transport of FD4 was even 1.84-fold enhanced in the presence of 0.5% (m/v) nanoparticles with the lowest free thiol group content. The higher the disulfide bond content within nanoparticles was, to a lower degree nanoparticles were hydrolyzed by cellulase. None of these nanoparticles showed pronounced cytotoxicity. Accordingly, HEC-cysteamine could be a promising excipient for nanoparticulate delivery systems for poorly absorbed drugs.

Thiolated Polycarbophil as an Adjuvant for Permeation Enhancement in Nasal Delivery of Antisense Oligonucleotides

The purpose of this study was to investigate the effect of thiolated polycarbophil as an adjuvant to enhance the permeation and improve the stability of a phosphorothioate antisense oligonucleotide (PTO-ODN) on the nasal mucosa. Polycarbophil-cysteine (PCP-Cys) was synthesized by the covalent attachment of L-cysteine to the polymeric backbone. Cytotoxicity tests were examined on human nasal epithelial cells from surgery of nasal polyps confirmed by histological studies. Deoxyribonuclease I activity in respiratory region of the porcine nasal cavity was analyzed by an enzymatic assay. The enzymatic degradation of PTO-ODNs on freshly excised porcine nasal mucosa was analyzed and protection of PCP-cysteine toward DNase I degradation was evaluated. Permeation studies were performed in Ussing-type diffusion chambers. PCP-Cys/GSH did not arise a remarkable mortal effect. Porcine respiratory mucosa was shown to possess nuclease activity corresponding to 0.69 Kunitz units/mL. PTO-ODNs were degraded by incubation with nasal mucosa. In the presence of 0.45% thiolated polycarbophil and 0.5% glutathione (GSH), this degradation process could be lowered. In the presence of thiolated polycarbophil and GSH the uptake of PTO-ODNs from the nasal mucosa was 1.7-fold improved. According to these results thiolated polycarbophil/GSH might be a promising excipient for nasal administration of PTO-ODNs.

An oral oligonucleotide delivery system based on a thiolated polymer: Development and in vitro evaluation

The purpose of this study was to develop and evaluate an oral oligonucleotide delivery system based on a thiolated polymer/reduced glutathione (GSH) system providing a protective effect toward nucleases and permeation enhancement. A polycarbophil-cysteine conjugate (PCP-Cys) was synthesized. Enzymatic degradation of a model oligonucleotide by DNase I and within freshly collected intestinal fluid was investigated in the absence and presence of PCP-Cys. Permeation studies with PCP-Cys/GSH versus control were performed in vitro on Caco-2 cell monolayers and ex vivo on rat intestinal mucosa. PCP-Cys displayed 223 ± 13.8 μmol thiol groups per gram polymer. After 4h, 61% of the free oligonucleotides were degraded by DNase I and 80% within intestinal fluid. In contrast, less than 41% (DNase I) and 60% (intestinal fluid) were degraded in the presence of 0.02% (m/v) PCP-Cys. Permeation studies revealed an 8-fold (Caco-2) and 10-fold (intestinal mucosa) increase in apparent permeability compared to buffer control. Hence, this PCP-Cys/GSH system might be a promising tool for the oral administration of oligonucleotides as it allows a significant protection toward degrading enzymes and facilitates their transport across intestinal membranes.

HEC-cysteamine particles: influence of particle size, zeta potential, morphology and sulfhydryl groups on permeation enhancing properties.

Within this study, the influence of particle size and zeta potential of hydroxyethyl cellulose–cysteamine particles on permeation enhancing properties was investigated. Particles were prepared by four different methods namely ionic gelation, spray drying, air jet milling and grinding. Particles prepared by grinding were additionally air jet milled. All particles were characterized in terms of particle size and zeta potential. The transport of fluorescein isothiocyanate-dextran 4 (FD4) across Caco-2 cell monolayers in the presence of these particles and the decrease in transepithelial electrical resistance (TEER) was evaluated. The cytotoxic effect of the particles was investigated using resazurin assay. Nanoparticles displaying a zeta potential of 3.3 ± 1.3 mV showed the highest enhancement of FD4 transport among all particles with a 5.83-fold improvement compared to buffer only. Due to the larger particle size, particles generated by grinding exhibited a lower capability in opening of tight junctions compared to smaller particles generated by air jet milling. In addition, the results of the transport studies were supported by the decrease in the TEER. All particle formulations tested were comparatively non-cytotoxic. Accordingly, the zeta potential and particle size showed a significant impact on the opening of tight junctions and hence could play an important role in the design of hydroxyethyl cellulose (HEC)-cysteamine-based nano- and micro-particles as drug delivery systems.

Molecular docking and ADME-toxicity studies of potential compounds of medicinal plants grown in Indonesia as an anti-rheumatoid arthritis

Rheumatoid arthritis (RA) is an autoimmune disease with recurrent bone destruction around the joints that could lead to permanent joint damage. DMARDs (Disease Modifying Anti-Rheumatoid Drugs) and NSAIDs (Non-Steroid Anti-Inflammatory Drugs) are the RA therapies with many side effects on long term use. Based on the ethnomedicine, there are many plants that could be found in Indonesia that contain the potential compounds as alternative RA therapies. The aim of this study is to assess the potential of compounds of various medicinal plants against multiple proteins that play an important role on RA through the molecular docking study and pharmacokinetic prediction. Hesperidin, EGCG (Epigallocatechin gallate), and mangiferin showed higher activity compared to the other compounds against TACE (TNF-α converting enzyme) which play an important role in the inhibition of TNF-α. Inhibition on it could suppress macrophage cell and T-cell activity by suppressing the regulation of cytokine secretion against inflammati...

Formulation and Cytotoxicity of Ribosome-Inactivating Protein Mirabilis Jalapa L. Nanoparticles Using Alginate-Low Viscosity Chitosan Conjugated with Anti-Epcam Antibodies in the T47D Breast Cancer Cell Line

Ribosome-inactivating protein (RIP) from Mirabilis jalapa L. leaves has cytotoxic effects on breast cancer cell lines but is less toxic towards normal cells. However, it can easily be degraded after administration so it needs to be formulated into nanoparticles to increase its resistance to enzymatic degradation. The objectives of this study were to develop a protein extract of M. jalapa L. leaves (RIP-MJ) incorporated into nanoparticles conjugated with Anti-EpCAM antibodies, and to determine its cytotoxicity and selectivity in the T47D breast cancer cell line. RIP-MJ was extracted from red-flowered M. jalapa L. leaves. Nanoparticles were formulated based on polyelectrolyte complexation using low viscosity chitosan and alginate, then chemically conjugated with anti-EpCAM antibody using EDAC based on carbodiimide reaction. RIP-MJ nanoparticles were characterised for the particle size, polydispersity index, zeta potential, particle morphology, and entrapment efficiency. The cytotoxicity of RIP-MJ nanoparticles against T47D and Vero cells was then determined with MTT assay. The optimal formula of RIP-MJ nanoparticles was obtained at the concentration of RIP-MJ, low viscosity chitosan and alginate respectively 0.05%, 1%, and 0.4% (m/v). RIP-MJ nanoparticles are hexagonal with high entrapment efficiency of 98.6%, average size of 130.7 nm, polydispersity index of 0.380 and zeta potential +26.33 mV. The IC50 values of both anti-EpCAM-conjugated and non-conjugated RIP-MJ nanoparticles for T47D cells (13.3 and 14.9 μg/mL) were lower than for Vero cells (27.8 and 33.6 μg/mL). The IC50 values of conjugated and non- conjugated RIP-MJ for both cells were much lower than IC50 values of non-formulated RIP-MJ (>500 μg/mL).

Effect of chitosan coating and bamboo FSC (fruit storage chamber) to expand banana shelf life

Chitosan has been widely used as fruit preserver and proven to extend the shelf life of many fruits, such as banana. However, banana producers and many industries in Indonesia still facing storage problems which may lead to mechanical damage of the fruits and ripening acceleration. Therefore, we have designed food storage chamber (FSC) based on bamboo material. Bamboo was selected because of material abundance in Indonesia, economically effective, and not causing an autocatalytic reaction to the ethylene gas produced by the banana. In this research, Cavendish banana that has reached the maturity level of mature green were coated with 1% chitosan and placed inside the FSC. As control treatments, uncoated banana was also placed inside the FSC as well as uncoated banana that were placed at open space. All of the treatments were placed at 25°C temperature and observed for 9 days. Water produced by respiration was reduced by the addition of charcoal inside a fabric pouch. The result showed that treatment using...

Pharmaceutical nanoparticle technologies: An approach to improve drug solubility and dissolution rate of Piroxicam

Pharmaceutical nanotechnology is employed to improve poor aqueous solubility of drug compounds which have limited in vivo bioavailability because of their low dissolution rate in the gastrointestinal fluids. Nanoparticle technology reduced particle size of piroxicam, proved to be effective in improving the oral bioavailability as a result of enhanced solubility and dissolution rate. To achieve this objective, the formulations were prepared by evaporative antisolvent precipitation methode. The first-line drug is dissolved in an organic solvent, and then quickly mixed with an aqueous solution of stabilizer media. The physical characteristics of nanoparticles, as shape, particle size, solubility and disolution rate of nanopiroxicam were evaluated. FTIR (Infrared Fourier Transform Spectroscopy), XRD (X-ray diffraction) and differential scanning calorimetr (DSC) of the microcrystals were studied. The results showed that the nanoprecipitation method was used to prepare biodegradable drugs of reproducible sizes of piroxicam in the range (300-400 nm) with spherical shape by addressing the effects of processing parameters. Nanopiroxicam successfully improved the solubility and in vitro dissolution is expected due to of amorphous from revealed by X-ray and Differential Scanning Calorimetry (DSC) studies. The dissolution rate of the nanoparticles was markedly enhanced by reducing the particle size and a subsequently increased surface area. Nanopiroxicam formulations improved solubility and dissolution rate of piroxicam. Dissolution test showed that the C5 and C60 values of nanopiroxicams were greater than that of the commercial drugs and that of untreated Piroxicam, respectively.

Formulation and Characterization of Kaffir Lime Oil Nanoemulsion

Kaffir lime oil has many health benefits. However, an obstacle to its commercial use is oxidation during storage. Nanoemulsions (particulate colloidal systems) have been shown to be suitable carriers for lipophilic essential oil constituents due to amphipathic compounds that facilitate solubility. The objectives of this study were to formulate thermodynamically stable kaffir lime oil nanoemulsions and to investigate their physicochemical properties. Air-dried leaves of kaffir lime were subjected to steam distillation to obtain essential oil. Preparation of nanoemulsions was done using the spontaneous emulsification method. Tween 80 and propylene glycol were selected as surfactant mix components. The oil phase consisted of Miglyol 812 as a carrier oil for kaffir lime oil while double-distilled water was used in the aqueous phase. The best formula with transmittance above 95% and highest essential oil content was selected. It contained 20% of Tween 80, 10% of propylene glycol, 1.25% Miglyol 812, and 3.75% kaffir lime essential oil. This formula was then characterized and its thermodynamic stability determined. The results showed that the average size of kaffir lime oil nanoemulsionsdroplets is 18.23+0.12 nm with poly dispersity index of 0.36+0.01. The system is thermodynamically stable and robustly withstood variations in temperature, centrifugation, and long-term storage. Additionally, the nanoemulsions had low viscosity, which may facilitate its development as a pharmaceutical compound.

Oral Delivery of Nucleic Acid Drugs

Nucleic acid molecules have emerged as versatile tools with promising utility in a variety of biochemical, diagnostic, and therapeutic applications. A parenteral administration of a nucleic acid is inconvenient because of pain, fear, and risks being associated with this type of application. The intestinal epithelium is considered to be an attractive site for oral delivery of therapeutic genes.