Current Drug Delivery - Volume 17, Issue 5, 2020

Hypoxic tumor cell sub-populations are highly resistant to radiotherapy and their presence frequently causes disease recurrence and death. Here, we described the physicochemical properties required to develop superior tumor-targeted hypoxia-activated modular prodrugs that liberate extremely short-lived bis(sulfonyl)hydrazines (BSHs) as reactive cytotoxins, thereby precisely focusing cytotoxic stress on these radio-resistant hypoxic sub-populations. Therefore, cytotoxic stress will be focused on radiation resistant areas and thus strongly synergizing with radiotherapy.

The passage of therapeutic molecules across the Blood-Brain Barrier (BBB) is a profound challenge for the management of the Central Nervous System (CNS)-related diseases. The ineffectual nature of traditional treatments for CNS disorders led to the abundant endeavor of researchers for the design the effective approaches in order to bypass BBB during recent decades. Cell-Penetrating Peptides (CPPs) were found to be one of the promising strategies to manage CNS disorders. CPPs are short peptide sequences with translocation capacity across the biomembrane. With special regard to their two key advantages like superior permeability as well as low cytotoxicity, these peptide sequences represent an appropriate solution to promote therapeutic/theranostic delivery into the CNS. This scenario highlights CPPs with specific emphasis on their applicability as a novel theranostic delivery system into the brain.

Background: Different approaches have been investigated to develop a preventive or therapeutic vaccine, although none of them has been fully practical. Therapeutic vaccines against HIV-1 have been studied with the aim of eliminating the virus from reservoir cells with or without HAART (Highly Active Antiretroviral Therapy). Fusion proteins with the most immunogenic features among conserved regions can facilitate this achievement in such a variable virus. To achieve the most immunogenic and also conserved regions, bioinformatics tools are widely used to predict antigens’ features before applying them. Objective: This study aimed at the in vitro evaluation of p24 -Nef fusion protein based on the previous in silico design to achieve a potential therapeutic subunit vaccine against HIV-1. Methods: The truncated form of p24-Nef using AAY flexible linker and the full protein were expressed and evaluated in the prokaryotic system and confirmed by western blotting. We also used pcDNA3.1 to transfect Lenti-X 293T cells. Moreover, lentiviral vectors were applied to produce recombinant virions harboring the genes of interest and cell transduction. Results: Both fusion proteins in a truncated and a full form were expressed and confirmed by Anti Nef polyclonal antibody in western blotting. Recombinant virions were generated and transduced Lenti-X 293T cells confirming by immunofluorescence microscope and p24 ELISA assay kit. Transduced cells were analyzed by SDS-PAGE and western blotting, which resulted in approved protein expression. Conclusion: Fusion protein of p24 and Nef is well expressed in eukaryotic cell lines according to its pre-evaluated features by bioinformatics tools.

Background: Photodynamic therapy which involves the use of photosensitizer molecule activated by a light source was proven very promising for the treatment of dermatological diseases, especially the resistant ones such as recalcitrant Plantar Warts (PW). Objective: However, its efficacy is hindered by the poor permeation of the photosensitizer molecule required to initiate skin photo-induced effects. Methods: In this manuscript, the efficiency of the nano-vesicular system (transfersomes) as a potential topical drug delivery system for the photosensitizer methylene blue (MB) was investigated following clinical Photodynamic Therapy (PDT) in patients suffering from PW. Results: Results revealed that MB transfersomal gel displayed a higher complete healing percentage for the lesions compared to the free MB gel (86.67% versus 53.57%) achieved at a lower number of treatment sessions (2.2 versus 4.14). Patients reported no signs of pain or inflammation, with no recurrence of the lesions during the follow up period of 8 months. Conclusion: PDT using transfersomal MB is an effective and safe therapeutic modality for the treatment of PW.

Background: Ophthalmology applies many different ways of delivering effective drugs to eye tissue for the prevention and treatment of diseases of various etiologies. The vast majority of ophthalmologists use traditional instillation of drugs in an eye disease. However, this method has a number of drawbacks, in particular, during instillation of drip forms of drugs, up to 80% of the drug is lost due to withdrawal of its tear fluid and rapid absorption by the mucous membrane of the eyes, which necessitates their frequent instillation to maintain the therapeutic concentration in the eyeball. Objective: The use of polymeric forms of bio soluble antiviral eye medicinal films of prolonged form in ophthalmic practice would allow introducing the active substance less often while maintaining its therapeutic concentration, reducing the dosage of the drug and the negative effect of frequent instillation. Methods: A method of obtaining polymeric forms of bio soluble nanostructured ophthalmic medicinal films is based on a composition of water-soluble Na-carboxymethylcellulose (Na-CMC) with a degree of substitution of 0.85 ± 2 and a polymerization degree of 630 ± 20 and a derivative of Nacarboxymethylcellulose containing a chemically bound natural polyphenol-gossypol in an amount of polymerization-630 ± 20 and a derivative of Na-carboxymethylcellulose containing chemically bound natural polyphenol-gossypol in an amount of 0 mole% (sodium salt of 2,3-diethoxy – 6 – O – carboxymethyl- (1 → 4) –β – D – ox glucose – oxy-hydroxyl – 2 – ethyl– (1 → 4) –β – D – ox glucose – diethyl hydroxyl-poly –2 – O – carboxymethyl- (1 → 4) - β - D glucose –2.6 - O –dicarboxymethyl- (1 → 4) –β – D glucose); this is the substance of the antiviral drug “CelAgrip”. Result: In this work the possibility of regulating the bio scission time and physicochemical parameters of ocular medicinal films has been shown, by varying the degree of substitution and degree of polymerization of sodium carboxymethylcellulose and the pH of their aqueous solutions. Conclusion: The most promising in terms of the prolongation effect and the absence of an irritating effect and transparency are films, obtained from solutions of the polymer-polymer composition of Na- CMC - a “CelAgrip” substance of a spherical shape with embedded nanoparticles of size 14-52 nm and a pH value of 7.6.

Purpose: Anthrax is a lethal bacterial disease caused by gram-positive bacterium Bacillus anthracis and vaccination is a desirable method to prevent anthrax infections. In the present study, DNA vaccine encoding a protective antigen of Bacillus anthracis was prepared and we investigated the influence of DNA electrotransfer in the skin on the induced immune response and biodistribution. Methods and Results: The tdTomato reporter gene for the whole animal in vivo imaging was used to assess gene transfer efficiency into the skin as a function of electrical parameters. Compared to that with 25 V, the transgene expression of red fluorescent protein increased significantly when a voltage of 90 V was used. Delivery of DNA vaccines expressing Bacillus anthracis protective antigen domain 4 (PAD4) with an applied voltage of 90 V induced robust PA-D4-specific antibody responses. In addition, the in vivo fate of anthrax DNA vaccine was studied after intradermal administration into the mouse. DNA plasmids remained at the skin injection site for an appropriate period of time after immunization. Intradermal administration of DNA vaccine resulted in detection in various organs (viz., lung, heart, kidney, spleen, brain, and liver), although the levels were significantly reduced. Conclusion: Our results offer important insights into how anthrax DNA vaccine delivery by intradermal electroporation affects the immune response and biodistribution of DNA vaccine. Therefore, it may provide valuable information for the development of effective DNA vaccines against anthrax infection.

Aim: This study was focused on the formulation of the multi-unit extended-release peroral delivery device of lamotrigine for better management of epilepsy. Background: The single-unit extended-release peroral preparations often suffer from all-or-none effect. A significant number of multi-unit delivery systems have been reported as a solution to this problem. But most of them are found to be composed of synthetic, semi-synthetic or their combination having physiological toxicity as well as negative environmental impact. Therefore, fabrication and formulation of multi-unit extended-release peroral preparations with natural, non-toxic, biodegradable polymers employing green manufacturing processes are being appreciated worldwide. Objective: Lamotrigine-loaded extended-release multi-unit beads have been fabricated with the incorporation of a natural polysaccharide Cassia fistula seed gum in calcium-cross-linked alginate matrix employing a simple green process and 2³ full factorial design. Methods: The total polymer concentration, polymer ratio and [CaCl2] were considered as independent formulation variables with two different levels of each for the experiment-design. The extended-release beads were then prepared by the ionotropic gelation method using calcium chloride as the crosslinkerions provider. The beads were then evaluated for drug encapsulation efficiency and drug release. ANOVA of all the dependent variables such as DEE, cumulative % drug release at 2h, 5h, 12h, rate constant and dissolution similarity factor (f2) was done by 2³ full factorial design using Design-Expert software along with numerical optimization of the independent variables in order to meet USP-reference release profile. Results: The optimized batch showed excellent outcomes with DEE of 84.7 ± 2.7 (%), CPR2h of 8.41± 2.96 (%), CPR5h of 36.8± 4.7 (%), CPR12h of 87.3 ± 3.64 (%) and (f2) of 65.9. Conclusion: This approach of the development of multi-unit oral devices utilizing natural polysaccharides might be inspiring towards the world-wide effort for green manufacturing of sustained-release drug products by the QbD route.

Aim: To investigate the application of Scrotal Heat Stress (SHS) and Pulsed Unfocused Ultrasound (PuFUS) to explore Blood-Testis Barrier (BTB) permeability in adult mice. Background: The BTB provides a stable microenvironment and a unique immune barrier for spermatogenesis. Meanwhile, it blocks macromolecular substances access, including therapeutic agents and antibodies, thereby it decreases the therapeutic or immunocontraception effects. Objectives: To determine the viability of these physical approaches in delivering macromolecular substances into seminiferous tubules. Materials & Methods: Mice were subjected to receive single SHS intervention at 39°C, 41°C, or 43°C for 30 min. Whereas, mice received the PuFUS intervention at 1.75w/cm2, 1.25w/cm2, and 2.5w/cm2 for 2 min, 5 min, and 10 min, respectively. The Biotin and macromolecular substances (IgG, IgM, and exosomes) were separately injected into the testicular interstitium at different times following SHS or PuFUS interventions, to observe their penetration through BTB into seminiferous tubules. Results: As detected by Biotin tracer, the BTB opening started from day-2 following the SHS and lasted for more than three days, whereas the BTB opening started from 1.5h following PuFUS and lasted up to 24h. Apparent penetration of IgG, IgM, and exosomes into seminiferous tubules was observed after five days of the SHS at 43°C, but none at 39°C, or any conditions tested with PuFUS. Conclusion: The current results indicate that SHS at 43°C comparatively has the potential for delivering macromolecular substances into seminiferous tubules, whereas the PuFUS could be a novel, quick, and mild approach to open the BTB. These strategies might be useful for targeted drug delivery into testicular seminiferous tubules. However, further studies are warranted to validate our findings.