Ligand-receptor interactions (LRIs) are the basis for all the biological processes taking place in living cells and have been exploited to develop and implement in medical field a number of highly sensitive biosensors for the detection of various biomarkers in complex biological fluids. Drug-target interactions, one of the LRIs, are important to understand the biological processes that further help in developing new and better therapeutic molecules. Biosensors based on these interactions give us an idea for the need of modification of existing drugs or to develop new drugs. Common approach to develop biosensors requires the labeling; however, label-free systems provide advantages in avoiding the chances of conformational changes, off-site labeling, and labeling-based hindrances, thus saving time and effort toward assay development. Preliminary drug screening assays are carried out in two-dimensional (2D) models, followed by animal models, which require huge capital investment to reach from bench-top to clinical trials, where only 21% of new compounds make way to phase-1 clinical trials. Three-dimensional culture or organoid culture or organ-on-chip technology has made way for predictive and complex in vitro approach that recapitulates human physiology and represents more similar in vivo behavior than 2D. Multiplexing and nanotechnology have remarkably enhanced the efficacy of biosensors and might lead to a generation of miniaturized biosensors and more than just point-of-care kits. This review provides in-depth analysis of different types of biosensor assays based on drug-target interactions, their advantages, and limitations based on cost, sensitivity, and selectivity and industrial applications.

Cisplatin is the most often used chemotherapy in the treatment of ovarian cancer (OC), however long-term usage leads to drug resistance and treatment failure. Silibinin is a sparingly water-soluble natural compound with well-known anticancer effects. The use of lipid-based delivery systems is a potential approach for enhancing silibinin's water solubility. In this study, nanostructured lipid carriers (NLCs) containing silibinin were prepared and their inhibitory effects were tested in combination with cisplatin against sensitive/resistant A2780 OC cells. Silibinin-loaded NLCs (silibinin-NLCs) were prepared by the hot homogenization method, and their size, shape, zeta potential (ZP), and encapsulation efficiency (EE), as well as their inhibitory effects, were examined in combination with cisplatin against sensitive/resistant A2780 OC cells. Formulation of silibinin-NLCs using cocoa butter led to spherical-shaped NLCs with a size of 95 nm and EE of 98%. The ZP and the dispersion index of the silibinin-NLCs were -27.12 ± 0.13 mv and 0.12 ± 0.04, respectively. The release kinetics of silibinin-NLCs was best fitted with the zero-order model. The combination of cisplatin and silibinin-NLCs sensitized the cisplatin-resistant A2780 OC cells and exhibited a more synergistic inhibitory effect on A2780 cells as compared with the combination of cisplatin and plain silibinin. The optimized silibinin-NLCs can be considered a suitable drug delivery system for the inhibition of cisplatin-resistant OC cells.

Propolis is rich in natural bioactive compounds, and considering its importance for many skin therapies, emulgel was prepared. This study examines how a propolis extract (PE) and Passiflora edulis seed (PS) oil emulgel affect rat deep skin wound healing. Based on preset criteria of maximum drug content and optimum drug permeation through the stratum corneum along with drug retention in the skin layers, an optimized emulgel formula based on Box-Behnken factorial design was prepared and used for subsequent in vitro and in vivo evaluations. In vivo wound-healing activities of emulgel and control treatments were investigated in a rat model. The optimized emulgel formula exhibited superior healing activity compared with plain PE suspension-treated rats on day 14 of wounding. Histopathological investigations of hematoxylin and eosin and Masson's Trichrome-stained skin sections supported this effect. Emulgel promotes cutaneous wound healing through a variety of mechanisms, including anti-inflammatory through modulation of cytokines tumor necrosis factor-α, interleukin (IL)-1β, and IL-6 production, and promotion of collagen fiber formation, all of which contribute to tissue remodeling. Furthermore, when compared with propolis suspension, emulgel showed significant antioxidant and anti-inflammatory effects. Emulgel significantly increased the skin's hydroxyproline level, antioxidant potential, wound contraction, increased penetration, and localized propolis deposition across the skin. Incorporation of PS oil into the emulgel accelerates the tissue regeneration process. The findings suggest that 5% propolis emulgel could be used as an alternative to treat wounds.

One of the most sought-after therapeutic targets for treating human cancers is the phosphoinositide 3-kinase; PI3k is an integral part of the PI3K/protein kinase B signaling arcade. This pathway is frequently activated in malignancies. Drug resistance and dose-limiting adverse effects are currently associated challenges with the existing anticancer chemotherapy. Therefore, in this research, a series of pyrimidine derivatives were designed and evaluated against human PI3K by using molecular docking analysis. The docking results were further verified by molecular dynamic simulation, which analyzed the strength of the macromolecular complex with respect to time. Compounds IV and XIV were found to be the most potent inhibitors of the human PI3K receptor with a high degree of stability within the active site of the target receptor for a timeframe of 50 ns. Thus, both of these compounds could be important drug candidates for the development of PI3K inhibitors as a prospective anticancer agent.

Intranasal route provides large surface area, avoids first-pass metabolism, and results in improved drug absorption. Intranasal delivery targets the drug to the brain for treatment of central nervous diseases viz migraine. The objective of the study was to formulate in situ nasal gel containing rizatriptan benzoate (RB)-loaded nanostructured lipid carriers (NLCs). NLCs were prepared by melt-emulsification ultrasonication method and optimized using 32 factorial design. Optimized NLCs were spherical with particle size of 189 nm, high drug encapsulation efficiency (84.5%), and 83.9% drug release at the end of 24 h. RB-loaded NLCs were incorporated into the liquid Carbopol 934P and Poloxamer 407 liquid gelling system to obtain in situ gel formation. The resultant product was assessed for gelling capacity, viscosity, and mucoadhesive strength. In vivo pharmacokinetic studies revealed significant therapeutic concentration of drug in the brain following intranasal administration with Cmax value of 5.1 ng/mL and area under the curve value of 829 ng/(min·mL). Significantly higher values of nose to brain targeting parameters, namely, drug targeting index (2.76) and nose to brain drug direct transport (63.69%) for RB-NLCs in situ nasal gel, confirmed drug targeting to brain through nasal route. The ex vivo nasal toxicity study showed no sign of toxicity to the nasal mucosa. Thus, the application of lipid carrier-loaded in situ gel proved potential for intranasal delivery of RB over the conventional gel formulations for efficient brain targeting.

Poorly aqueous soluble active pharmaceutical ingredients are highly risky development candidates and remain a concern of pharmaceutical industries in drug discovery and development processes. Pharmaceutical industries are putting significant efforts into the target identification and lead candidate development using combinatorial chemistry. About 40% of compounds arising from combinatorial screening are poorly water soluble. Pharmaceutical industries evolved over this challenge by coming up with reproducible and scalable particle size reduction or by identifying alternate morphs. Another important area where pharmaceutical industries are working is solid dispersion technology. With the emergence of the hot-melt extrusion and spray drying approach, many molecules have been brought to the market using solid dispersion technology from the discovery phase by improving bioavailability and thereby efficacy. Although the solid solution technology in the last 60 years evolved from eutectic mixtures, solid dispersions using water-soluble polymers, and enteric polymers especially hydroxypropyl methylcellulose acetate succinate (HPMCAS), still there is no preformulation tool to identify correct polymer or polymer combination at the early stage of development. Thus, this leads to the urgent need to focus on the design and development of third-generation solid dispersions for the unmet needs of the industries and society.

It is hypothesized that etoposide/VP-16 nanomicellar formulation (VP-16 NMF) utilizing D-α-Tocopherol polyethylene glycol 1000 succinate (TPGS) can improve etoposide solubility and anticancer activity. The following four different concentrations of TPGS: 3, 6, 8, and 10 wt% were used to solubilize the drug. Among these four formulations, 10 wt% of TPGS loaded with VP-16 NMF dramatically enhanced etoposide apparent solubility by 26-folds compared with the native drug. The physicochemical properties of the optimized formulation were further analyzed by dynamic light scattering, X-ray powder diffraction, scanning electron microscopy, proton nuclear magnetic resonance (1HNMR) and Fourier transform infrared spectroscopy. Liquid chromatography tandem-mass spectrometry (LC-MS/MS) was used to assess solubility and intracellular uptake of the drug from the NMF. Cell viability assay ([3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H tetrazolium solution [MTS]) was performed on MCF-7 and MCF-10A cell lines to assess intracellular uptake and anticancer activity of etoposide. The MTS assay results showed that the VP-16 NMF platform provides a higher anticancer activity than the native VP-16 on the MCF-7 cells line as it integrates a dual anticancer activity of VP-16 and TPGS. LC-MS/MS data showed a threefold increase in cellular uptake of VP-16 NMF in MCF-7 cell line compared with the native etoposide. These data suggest that an optimal TPGS concentration can improve VP-16 bioavailability and efficacy with potential benefits for chemotherapy.

ASSAY and Drug Development TechnologiesVol. 19, No. 7 Letters to the EditorRe: “Letter to the Editor: Repurposing of an Antisepsis Drug in COVID-19 Patients,” by Kumar et al.Rajni RaniRajni RaniAddress correspondence to: Rajni Rani, PhD, National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi 110067, India E-mail Address: [email protected]Molecular Immunogenetics Group, National Institute of Immunology, New Delhi, India.Search for more papers by this authorPublished Online:4 Oct 2021https://doi.org/10.1089/adt.2020.1002AboutSectionsView articleView Full TextPDF/EPUB Permissions & CitationsPermissionsDownload CitationsTrack CitationsAdd to favorites Back To Publication ShareShare onFacebookXLinked InRedditEmail View articleFiguresReferencesRelatedDetails Volume 19Issue 7Oct 2021 InformationCopyright 2021, Mary Ann Liebert, Inc., publishersTo cite this article:Rajni Rani.Re: “Letter to the Editor: Repurposing of an Antisepsis Drug in COVID-19 Patients,” by Kumar et al..ASSAY and Drug Development Technologies.Oct 2021.408-409.http://doi.org/10.1089/adt.2020.1002Published in Volume: 19 Issue 7: October 4, 2021Online Ahead of Print:August 31, 2021PDF download