Papain Loaded Poly(ε-Caprolactone) Nanoparticles: In-silico and In-Vitro Studies

Liposomes and transferosomes in the delivery of papain for the treatment of keloids and hypertrophic scars

Hypertrophic scars and keloids are characterized by an excessive collagen deposition. The available treatment options are invasive and can result in recurrence of scar formation. Using liposomes and transferosomes for the topical delivery of papain, a proteolytic enzyme, can be effective treatment. The objective of the study is to formulate papain-loaded liposomes and transferosomes, characterize the formulations, and study in vitro permeation using shed snake skin and Sprague-Dawley rat skin as models for stratum corneum and full thickness skin. Papain-loaded liposomes and transferosomes were formulated using the thin-film hydration method for the delivery of papain across the stratum corneum barrier. An in vitro permeation study carried out using shed-snake skin and Sprague-Dawley rat skin models showed that transferosomes were able to deliver papain across the stratum corneum barrier, while papain solution and papain liposomes were not able to cross the barrier. However, transferosomes were not able to deliver papain across the full thickness rat skin model suggesting the deposition of papain loaded transferosomes in the epidermal or dermal layer of skin. In addition, an ex-vivo model was used to analyze the effect of papain exposure on the morphology of the epidermis taken from rat skin exposed to papain solution, papain in transferosomes and papain in liposomes. Papain in solution resulted in a noticeable degradation of the epidermis, but when embedded in either transferosomes or liposomes there was no noticeable change when compared to control animals. The cytotoxicity study performed using HeLa cells showed that the cells were viable at papain concentrations lower than 0.01 mg/ml.

Hybridization of papain molecules and DNA-wrapped single-walled carbon nanotubes evaluated by atomic force microscopy in fluids

Although various conjugates of single-walled carbon nanotubes (SWNTs) and biomolecules, such as nanobiosensors and nanobiodevices, have been reported, the conjugation of papain and SWNTs have not been reported because of the formation of unexpected aggregates. In this study, atomic force microscopy (AFM) in liquid was used to investigate the interactions between papain and DNA-wrapped SWNTs (DNA-SWNTs) at two different pH values (pH 3.0 and 10.5). The direct AFM observation of the mixture of papain and DNA-SWNTs confirmed the aggregation of papain molecules with DNA-SWNTs in the buffer solutions. The numerous and non-uniform adsorption of papain molecules onto DNA-SWNTs was more pronounced at pH 3.0 than that at pH 10.5. Furthermore, thick conjugates appeared when papain and DNA-SWNTs were simultaneously mixed. The near-infrared photoluminescence spectra of the SWNTs drastically changed when the papain molecules were injected into the DNA-SWNT suspension at pH 3.0. Thus, the regulation of electrostatic interactions is a key aspect in preparing optimal conjugates of papain and DNA-SWNTs. Furthermore, although previous papers reported AFM images of dried samples, this study demonstrates the potential of AFM in liquid in evaluating individual bioconjugates of SWNTs.

Molecular docking studies of YKT tripeptide and drug delivery system with poly(ε-caprolactone) nanoparticles

Tyrosyllysylthreonine (YKT) is a peptide structure that contains three different amino acids in its structure and has anticancer properties. The main purpose of this study is to reveal the structural interactions of the peptide and to increase the efficiency of the peptide with nanoformulation. For these purposes, YKT-loaded poly(ε-caprolactone) (PCL) nanoparticles (NPs) were synthesized using the double-emission precipitation method and the obtained NPs were characterized with a Zeta Sizer, UV-Vis, Fourier transform infrared-attenuated total reflection spectrometers, scanning electron microscopy, and transmission electron microscopy. The in vitro release profile of the peptide-loaded PCL NPs was determined. In molecular modeling studies, PCL, PCL-polyvinyl alcohol (PVA), and PCL-PVA-YKT systems were simulated in an aqueous medium by molecular dynamics simulations, separately. The information about the interactions between the YKT tripeptide and the epidermal growth factor and androgen, estrogen, and progesterone receptors were obtained with the molecular docking study. Additionally, the ADME profile of YKT was determined as a result of each docking study. In conclusion, tripeptide-based nanodrug development studies of the YKT tripeptide are presented in this study.

Semi-Solid Pharmaceutical Formulations for the Delivery of Papain Nanoparticles

Papain is a therapeutic enzyme with restricted applications due to associated allergenic reactions. Papain nanoparticles have shown to be safe for biomedical use, although a method for proper drug loading and release remains to be developed. Thus, the objective of this work was to develop and assess the stability of papain nanoparticles in a prototype semi-solid formulation suitable for dermatological or topical administrations. Papain nanoparticles of 7.0 ± 0.1 nm were synthesized and loaded into carboxymethylcellulose- and poly(vinyl alcohol)-based gels. The formulations were then assayed for preliminary stability, enzyme activity, cytotoxicity studies, and characterized according to their microstructures and protein distribution. The formulations were suitable for papain nanoparticle loading and provided a stable environment for the nanoparticles. The enzyme distribution along the gel matrix was homogeneous for all the formulations, and the proteolytic activity was preserved after the gel preparation. Both gels presented a slow release of the papain nanoparticles for four days. Cell viability assays revealed no potential cytotoxicity, and the presence of the nanoparticles did not alter the microstructure of the gel. The developed systems presented a potential for biomedical applications, either as drug delivery systems for papain nanoparticles and/or its complexes.

New anti-viral drugs for the treatment of COVID-19 instead of favipiravir

The SARS-CoV-2 virus is a major problem in the world right now. Currently, all the attention of research centers and governments globally are focused on the investigation of vaccination studies and the discovery of small molecules that inhibit the SARS-CoV-2 virus in the treatment of patients. The goal of this study was to locate small molecules to be used against COVID19 instead of favipiravir. Favipiravir analogues were selected as drug candidates from the PubChem web tool. The RNA dependent RNA polymerase (RdRp) protein was selected as the target protein as favipiravir inhibits this protein in the human body. Initially, the inhibition activity of the studied compounds against RdRp of different virus types was investigated. Then, the inhibition properties of selected drug candidates and favipiravir were examined in detail against SARS-CoV-2 RdRp proteins. It was found that 2-oxo-1H-pyrazine-3-carboxamide performed better than favipiravir in the results of molecular docking, molecular mechanics Poisson-Boltzmann surface area (MM-PSBA) calculations, and ADME analyses.

Communicated by Ramaswamy H. Sarma

The biological activities, molecular docking studies, and anticancer effects of 1-arylsuphonylpyrazole derivatives

This work is devoted to definition of the direction of reaction between 1-benzenesulfonylimino pyridinium chloride and α- or β-halo-containing sulfamides, chloroacetic acid, 1-chloro-2,3-dihydroxypropane, etc. The optimal conditions for the synchronous reaction of heterocyclization are determined. Benzenesulfonyliminopyridinium chloride was obtained to form pyrazolopyridines with 1,2-polarophiles, and pyridazine pyridines with 1,3-polarophiles. These novel derivatives were found as effective inhibitors of the α-glycosidase with K_i values in the range of 13.66 ± 2.63-60.63 ± 12.71 nM. The molecules (II-X) against enzyme were compared theoretically with the help of molecular docking to compare biological activities. The results were compared with the numerical values of the parameters obtained from molecular docking calculations and found to be in great agreement with the experimental results. However, ADME analysis of molecules was performed. Also, the compounds exhibited significant anticancer effect depending on the doses administered.Communicated by Ramaswamy H. Sarma.