Polycaprolactone - Vitamin E TPGS micelles for delivery of paclitaxel: In vitro and in vivo evaluation.

This study aimed to present findings on a paclitaxel (PTX)-loaded polymeric micellar formulation based on polycaprolactone-vitamin E TPGS (PCL-TPGS) and evaluate its in vitro anticancer activity as well as its in vivo pharmacokinetic profile in healthy mice in comparison to a marketed formulation. Micelles were prepared by a co-solvent evaporation method. The micelle's average diameter and polydispersity were determined using dynamic light scattering (DLS) technique. Drug encapsulation efficiency was assessed using an HPLC assay. The in vitro cytotoxicity was performed on human breast cancer cells (MCF-7 and MDA-MB-231) using MTT assay. The in vivo pharmacokinetic profile was characterized following a single intravenous dose of 4 mg/kg to healthy mice. The mean diameters of the prepared micelles were ≤ 100 nm. Moreover, these micelles increased the aqueous solubility of PTX from ∼0.3 µg/mL to reach nearly 1 mg/mL. While the PTX-loaded micelles showed an in vitro cytotoxicity comparable to the marketed formulation (Ebetaxel), drug-free PCL-TPGS micelles did not show any cytotoxic effects on both types of breast cancer cells (∼100% viability). Pharmacokinetics of PTX as part of PCL-TPGS showed a significant increase in its volume of distribution compared to PTX conventional formulation, Ebetaxel, which is in line with what was reported for clinical nano formulations of PTX, i.e., Abraxane, Genexol-PM, or Apealea. The findings of our studies indicate a significant potential for PCL-TPGS micelles to act as an effective system for solubilization and delivery of PTX.

Sorafenib and Piperine co-loaded PLGA nanoparticles: Development, characterization, and anti-cancer activity against hepatocellular carcinoma cell line.

Hepatocellular carcinoma (HCC) exhibits high mortality rates in the advanced stage (>90 %). Sorafenib (SORA) is a targeted therapy approved for the treatment of advanced HCC; however, the reported response rate to such a therapeutic is suboptimal (<3%). Piperine (PIP) is an alkaloid demonstrated to exert a direct tumoricidal activity in HCC and improve the pharmacokinetic profiles of anticancer drugs including SORA. In this study, we developed a strategy to improve efficacy outcomes in HCC using PIP as an add-on treatment to support the first-line therapy SORA using biodegradable Poly (D, L-Lactide-co-glycolide, PLGA) nanoparticles (NPs). SORA and PIP (both exhibit low aqueous solubility) were co-loaded into PLGA NPs (PNPs) and stabilized with various concentrations of polyvinyl alcohol (PVA). The SORA and PIP-loaded PNPs (SP-PNPs) were characterized using Fourier Transform Infrared (FTIR) Spectroscopy, X-ray Powder Diffraction (XRD), Dynamic Light Scattering (DLS), and Scanning Electron Microscopy (SEM), Release of these drugs from SP-PNPs was investigated in vitro at both physiological and acidic pH, and kinetic models were employed to assess the mechanism of drug release. The in vitro efficacy of SP-PNPs against HCC cells (HepG2) was also evaluated. FTIR and XRD analyses revealed that the drugs encapsulated in PNPs were in an amorphous state, with no observed chemical interactions among the drugs or excipients. Assessment of drug release in vitro at pH 5 and 7.4 showed that SORA and PIP loaded in PNPs with 0.5 % PVA were released in a sustained manner, unlike pure drugs, which exhibited relatively fast release. SP-PNPs with 0.5 % PVA were spherical, had an average size of 224 nm, and had a high encapsulation efficiency (SORA âˆ¼ 82 %, PIP âˆ¼ 79 %), as well as superior cytotoxicity compared to SORA monotherapy in vitro. These results suggest that combining PIP with SORA using PNPs may be an effective strategy for the treatment of HCC and may set the stage for a comprehensive in vivo study to evaluate the efficacy and safety of this novel formulation using a murine HCC model.

Therapeutic benefits of quercetin in traumatic brain injury model exposed to cigarette smoke.

Scientific evidences reported the deleterious effect of cigarette smoking or passive smoking on brain health particularly cognitive functions, blood-brain barrier (BBB) permeability, up-regulation of inflammatory cascades, and depletion of the antioxidant system. These combined effects become more progressive in the events of stroke, traumatic brain injury (TBI), and many other neurodegenerative diseases. In the current study, we investigated the long-term administered therapeutic potential of quercetin in ameliorating the deleterious neurobiological consequences of chronic tobacco smoke exposure in TBI mice. After exposure to 21 days of cigarette smoke and treatment with 50 mg/kg of quercetin, C57BL/6 mice were challenged for the induction of TBI by the weight drop method. Subsequently, a battery of behavioral tests and immunohistochemical analyses revealed the beneficial effect of quercetin on the locomotive and cognitive function of TBI + smoked group mice (p < 0.05 vs control sham). Immunohistochemistry analysis (Nrf2, HO-1, NFkB, caspase 3) demonstrated a marked protection after 21 days of quercetin treatment in the chronic tobacco smoking group possibly by up-regulation of antioxidant pathways, and decreased apoptosis. In conclusion, our findings support the therapeutic effectiveness of quercetin in partly protecting the central neurological functions that become aberrantly impaired in combined habitual cigarette-smoking individuals impacted with TBI.

Topical Application of Linezolid-Loaded Chitosan Nanoparticles for the Treatment of Eye Infections.

Linezolid (LZ) loaded chitosan-nanoparticles (CSNPs) was developed by the ionic-gelation method using Tripolyphosphate-sodium as a crosslinker for topical application for the treatment of bacterial eye infections. Particles were characterized by Zeta-Sizer (Malvern Nano-series). TEM was used for structural morphology. Encapsulation and drug loading were estimated by measuring the unencapsulated drug. In-vitro drug release in STF (pH 7) was performed through a dialysis membrane. Storage stability of LZ-CSNPs was checked at 25 °C and 40 °C for six months. The antimicrobial potency of NPs was evaluated on different Gram-positive strains. Ocular irritation and pharmacokinetic studies were completed in rabbits. Ex-vivo transcorneal permeation of the drug was determined through the rabbit cornea. Ionic interaction among the oppositely charged functional groups of CS and TPP generated the CSNPs. The weight ratio at 3:1, wt/wt (CS/TPP) with 21.7 mg of LZ produced optimal NPs (213.7 nm with 0.387 of PDI and +23.1 mV of ZP) with 71% and 11.2% encapsulation and drug loading, respectively. Around 76.7% of LZ was released from LZ-AqS within 1 h, while 79.8% of LZ was released from CSNPs at 12 h and 90% at 24 h. The sustained drug release property of CSNPS was evaluated by applying kinetic models. The linearity in the release profile suggested that the release of LZ from CSNPs followed the Higuchi-Matrix model. LZ-CSNPs have shown 1.4 to 1.6-times improved antibacterial activity against the used bacterial strains. The LZ-CSNPs were "minimally-irritating" to rabbit eyes and exhibited 4.4-times increased transcorneal permeation of LZ than from LZ-AqS. Around 3-, 1.2- and 3.1-times improved Tmax, Cmax, and AUC0-24 h, respectively were found for LZ-CSNPs during the ocular pharmacokinetic study. AqS has shown 3.1-times faster clearance of LZ. Conclusively, LZ-CSNPs could offer a better alternative for the prolonged delivery of LZ for the treatment of bacterial infections in the eyes.

Chitosan loaded RNA polymerase inhibitor nanoparticles increased attenuation in toxin release from Streptococcus pneumonia.

Background: Multidrug-resistant (MDR) bacterial infections have become an emerging health concern around the world. Antibiotics resistance among S. pneumoniae strains increased recently contributing to increase in incidence of pneumococcal infection. This necessitates the discovery of novel antipnemococcal such as compound C3-005 which target the interaction between RNA polymerase and σ factors. Chitosan nanoparticles (CNPs) exhibited antibacterial activity including S. pneumonia. Therefore, the aims of the current investigation were to formulate CNPs loaded with C3-005 and characteristic their antimicrobial properties against S. pneumonia. Methods: The CNPs and C3-005 loaded CNPs were produced utilizing ionic gelation method, and their physicochemical characteristics including particle size, zeta potential, polydispersity index (PDI), encapsulation efficiency (EE%), and in vitro release profile were studied. Both differential scanning calorimetry (DSC) and fourier transform infrared spectroscopy (FTIR) were used for chemical characterization. The synthesized NPs' minimum inhibitory concentration (MIC) was determined using killing assay and broth dilution method, and their impact on bacteria induced hemolysis were also studied. Results: The NPs encapsulating C3-005 were successfully prepared with particle size of 343.5 nm ± 1.3, zeta potential of 29.8 ± 0.37, and PDI of 0.20 ± 0.03. 70 % of C3-005 were encapsulated in CNPs and sustained release pattern of C3-005 from CNPs was revealed by an in vitro release study. CNPs containing C3-005 exhibited higher antipnomcoccal activity with MIC50 of 30 µg/ml when compared with C3-005 and empty CNPs alone. The prepared C3-CNPs showed a reduction of bacterial hemolysis in a concentration-related (dependent) manner and was higher than C3-005 alone. Conclusions: The findings of this study showed the potential for using C3-005 loaded CNPs to treat pneumococcal infection.

ON-1 and BA-IX Are the Dominant Sub-Genotypes of Human Orthopneumovirus A&B in Riyadh, Saudi Arabia.

Human orthopneumovirus (HOPV) is the major viral pathogen responsible for lower respiratory tract infections (LRTIs) in infants and young children in Riyadh, Saudi Arabia. Yet, predominant HOPV subtypes circulating in this region and their molecular and epidemiological characteristics are not fully ascertained. A total of 300 clinical samples involving nasopharyngeal aspirates (NPAs), throat swabs, and sputum were collected during winter seasons of 2019/2020 and 2021/2022 for HOPV subtyping and genotyping. Of the 300 samples, HOPV was identified in 55 samples (18.3%) with a distinct predominance of type A viruses (81.8%) compared to type B viruses (18.2%). Importantly, the ON1 strain of HOPV-A and BA-IX strain of HOPV-B groups were found to be responsible for all the infections. Sequence analysis revealed a duplication region within 2nd HVR of G protein gene of ON1 and BA-IX strains. This nucleotide duplication exerted a profound effect on protein length and affinity towards cell receptors. Further, these modifications may aid the HOPV in immune evasion and recurrent infections. Data from this study showed that ON-1 genotype of HOPV-A and BA-IX genotype of HOPV-B were dominant in Riyadh, Saudi Arabia. Further, a duplication of sequence within 2nd HVR of G protein gene was found.

Recent nanotechnology advancements to treat multidrug-resistance pancreatic cancer: Pre-clinical and clinical overview.

Pancreatic cancer (PC) remains one of the most lethal and incurable forms of cancer and has a poor prognosis. One of the significant therapeutic challenges in PC is multidrug resistance (MDR), a phenomenon in which cancer cells develop resistance toward administered therapy. Development of novel therapeutic platforms that could overcome MDR in PC is crucial for improving therapeutic outcomes. Nanotechnology is emerging as a promising tool to enhance drug efficacy and minimize off-target responses via passive and/or active targeting mechanisms. Over the past decade, tremendous efforts have been made to utilize nanocarriers capable of targeting PC cells while minimizing off-target effects. In this review article, we first give an overview of PC and the major molecular mechanisms of MDR, and then we discuss recent advancements in the development of nanocarriers used to overcome PC drug resistance. In doing so, we explore the developmental stages of this research in both pre-clinical and clinical settings. Lastly, we discuss current challenges and gaps in the literature as well as potential future directions in the field.

Bacteriophage carriers localize in the brain of a rat model of neonatal hypoxic-ischemic encephalopathy.

BACKGROUND: Neonatal hypoxic-ischemic encephalopathy arises from a reduction of oxygen and blood supply to the infant brain and can lead to severe brain damage and life-long disability. The damage is greatest at the irreversibly injured necrotic core, whereas the penumbra is the surrounding, potentially salvageable tissue populated with a mix of alive and dying cells. To date, there exists no method for targeting drugs to the brain damage. METHODS AND MAJOR RESULTS: Bacteriophages are viruses that propagate in bacteria but are biocompatible in humans and also amenable to genetic and chemical modification in a manner distinctive from conventional therapeutic nanoparticles. Here, a library of M13 bacteriophage was administered into a rat model of hypoxic-ischemic encephalopathy, and unique bacteriophage clones were confirmed to localize in healthy brain tissue versus the core and penumbra zones of injury. CONCLUSIONS: For the first time, there is a potential to directly deliver therapeutics to different regions of the neonatal brain injury.

Effect of amino acid composition of elastin-like polypeptide nanoparticles on nonspecific protein adsorption, macrophage cell viability and phagocytosis.

Development of elastin-like polypeptide (ELP) biomaterials is widespread, but information critical for clinical deployment is limited, with biocompatibility studies focused on a narrow cross-section of ELP sequences. Macrophages can impair biomaterial systems by degrading or isolating the biomaterial and by activating additional immune functions. Their phagocytic response will reveal early immune biocompatibility of ELP nanoparticles (NPs). This study examines that response, induced by the adsorbed protein corona, as a function of ELP guest amino acid, chain length and NP diameter. The breadth of proteins adsorbed to ELP NPs varied, with valine-containing ELP NPs adsorbing fewer types of proteins than leucine-containing constructs. Particle diameter was also a factor, with smaller leucine-containing ELP NPs adsorbing the broadest range of proteins. Macrophage viability was unaffected by the ELP NPs, and their phagocytic capabilities were unimpeded except when incubated with a 500 nm valine-containing 40-mer. This NP significantly decreased the phagocytic capacity of macrophages relative to the control and to a corresponding 500 nm leucine-containing 40-mer. NP size and the proportion of opsonin to dysopsonin proteins likely influenced this outcome. These results suggest that certain combinations of ELP sequence and particle size can result in an adsorbed protein corona, which may hinder macrophage function.

Design and Development of D‒α‒Tocopheryl Polyethylene Glycol Succinate‒block‒Poly(ε-Caprolactone) (TPGS-b-PCL) Nanocarriers for Solubilization and Controlled Release of Paclitaxel.

The objective of this study was to synthesize and characterize a set of biodegradable block copolymers based on TPGS-block-poly(ε-caprolactone) (TPGS-b-PCL) and to assess their self-assembled structures as a nanodelivery system for paclitaxel (PAX). The conjugation of PCL to TPGS was hypothesized to increase the stability and the drug solubilization characteristics of TPGS micelles. TPGS-b-PCL copolymer with various PCL/TPGS ratios were synthesized via ring opening bulk polymerization of ε-caprolactone using TPGS, with different molecular weights of PEG (1-5 kDa), as initiators and stannous octoate as a catalyst. The synthesized copolymers were characterized using 1H NMR, GPC, FTIR, XRD, and DSC. Assembly of block copolymers was achieved via the cosolvent evaporation method. The self-assembled structures were characterized for their size, polydispersity, and CMC using dynamic light scattering (DLS) technique. The results from the spectroscopic and thermal analyses confirmed the successful synthesis of the copolymers. Only copolymers that consisted of TPGS with PEG molecular weights ≥ 2000 Da were able to self-assemble and form nanocarriers of ≤200 nm in diameter. Moreover, TPGS2000-b-PCL4000, TPGS3500-b-PCL7000, and TPGS5000-b-PCL15000 micelles enhanced the aqueous solubility of PAX from 0.3 µg/mL up to 88.4 ug/mL in TPGS5000-b-PCL15000. Of the abovementioned micellar formulations, TPGS5000-b-PCL15000 showed the slowest in vitro release of PAX. Specifically, the PAX-loaded TPGS5000-b-PCL15000 micellar formulation showed less than 10% drug release within the first 12 h, and around 36% cumulative drug release within 72 h compared to 61% and 100% PAX release, respectively, from the commercially available formulation (Ebetaxel®) at the same time points. Our results point to a great potential for TPGS-b-PCL micelles to efficiently solubilize and control the release of PAX.

The influence of demographics on influenza vaccine awareness and hesitancy among adults visiting educational hospital in Saudi Arabia.

OBJECTIVE: To understand the influence of demographics and education levels on awareness levels, and on the prevalence of hesitancy to receive the influenza vaccine among adult patients at King Saud University Medical City (KSUMC). METHOD: A crosssectional study in the outpatient pharmacy area at KSUMC was conducted. Data was collected from January 1 to January 31, 2020. A total of 318 random adult patients were encountered and a predesigned survey was administered. After capturing demographic information, respondents were categorized into 3 groups: group A consisted of respondents who had never heard of the influenza vaccine; group B was comprised of respondents who answered that they had never received the influenza vaccine; and group C included respondents who answered that they had received at least one influenza vaccine. RESULTS: Out of the 317 survey respondents, 36 (11%) had never heard of the influenza vaccine (Group A). Of the remaining 281 (89%), 122 (39%) had not received the vaccine (Group B), whereas 159 (50%) had received it (Group C). Chi-square test results indicated a significant association between age group and awareness of the vaccine (p = .023). Moreover, there was a significant association between education level and awareness of the vaccine (p = .002). The prevalence of vaccination hesitancy was 42%. Chi-square test results indicated a significant association between gender and vaccination hesitancy (p < .001), and between education level and vaccination hesitancy (p = .011). CONCLUSION: Influenza vaccination hesitancy is prevalent among the study's population. Further efforts by health care providers and public health services may be necessary to educate the community regarding the influenza vaccine's safety and efficacy.

Human plasma protein adsorption to elastinlike polypeptide nanoparticles.

Elastin-like polypeptides (ELPs) are being developed for numerous biomedical applications. There is a limited understanding of ELP biocompatibility, with conflicting results in the literature. Protein adsorption is the fate determining event for blood-contacting biomaterials. The aim of this study is to elucidate the biocompatibility of ELP-based nanoparticles by examining the adsorbed proteome from platelet poor human plasma as a function of the physicochemical properties of these nanoparticles: diameter, amino acid hydrophobicity, and chain length. It was found that all ELP constructs had adsorbed an extremely large amount of albumin and high levels of immunoglobulin G and activated complement factor 3. Variations in the compositions of the proteomes across the eight nanoparticle systems studied were observed for plasminogen, fibronectin, activated fibrinogen, and coagulation modulating antithrombin and alpha2 macroglobulin. Plasma clotting experiments showed that ELP-based nanoparticles slightly inhibited normal blood clotting, with shorter and/or more hydrophilic constructs showing a greater difference from the control than longer or more hydrophobic constructs. These results indicate that ELP nanoparticles, regardless of chain length, particle diameter, or amino acid hydrophobicity, may have the potential to stimulate a humoral immune response via immunoglobulin G and activated complement factor 3 despite the large amounts of albumin adsorbed at the blood-material interface.

Self-assembly/disassembly hysteresis of nanoparticles composed of marginally soluble, short elastin-like polypeptides.

BACKGROUND: Elastin-like polypeptides (ELPs) are a fascinating biomaterial that has undergone copious development for a variety of therapeutic applications including as a nanoscale drug delivery vehicle. A comprehensive understanding of ELP self-assembly is lacking and this knowledge gap impedes the advancement of ELP-based biomaterials into the clinical realm. The systematic examination of leucine-containing ELPs endeavors to expand existing knowledge about fundamental assembly-disassembly behaviours. RESULTS: It was observed that these marginally soluble, short ELPs tend to behave consistently with previous observations related to assembly-related ELP phase transitions but deviated in their disassembly. It was found that chain length, concentration and overall sequence hydrophobicity may influence the irreversible formation of sub-micron particles as well as the formation of multi-micron scale, colloidally unstable aggregates. Amino acid composition affected surface charge and packing density of the particles. Particle stability upon dilution was found to vary depending upon chain length and hydrophobicity, with particles composed of longer and/or more hydrophobic ELPs being more resistant to disassembly upon isothermal dilution. CONCLUSIONS: Taken together, these results suggest marginally soluble ELPs may self-assemble but not disassemble as expected and that parameters including particle size, zeta potential and dilution resistance would benefit from widespread systematic evaluations. This information has the potential to reveal novel preparation methods capable of expanding the utility of all existing ELP-based biomaterials.

Using Properties of Tumor Microenvironments for Controlling Local, On-Demand Delivery from Biopolymer-Based Nanocarriers.

BACKGROUND: The 'tumor microenvironment' comprised of tumor cells, non-malignant stromal tissues, signaling molecules and the extracellular matrix. Tumor microenvironment has unique physical and physiological characteristics including vascular abnormalities, hypoxia, acidic pH, specific enzymes and growth factors upregulation and high reducing potential. It is these endogenous properties of the tumor environment that can be used to trigger the release of cancer therapeutics both locally and as a function of disease state. Biopolymers such as proteins, polypeptides and polysaccharides are actively being designed to be bioresponsive nanocarriers for drug delivery due to their relative biocompatibility, biodegradability and low immunogenicity. OBJECTIVE: This review focuses on the use of physicochemical attributes of the endogenous tumor microenvironment to provide the impetus for on-demand release of therapeutics from biopolymer-based nanocarriers that are sensitive to pH, enzymes, redox conditions and combinations thereof. CONCLUSION: The development of multifunctional nanocarriers based upon a rational approach for targeting and delivering therapeutics to tumors is an area of active research. Despite the huge amount of work done in this area, especially using pH as a means of eliciting drug release at tumor sites, there is a dearth of work whereby different stages during tumor development are targeted for treatment. Although nanocarriers that are able to react to multiple components of the tumor microenvironment are starting to become common-place, it seems that the ability to release various factors at specific times crucial to therapy has not been studied to a large extent as a means of regaining tissue homeostasis.

High-yield recombinant expression and purification of marginally soluble, short elastin-like polypeptides.

The protocol described here is designed as an extension of existing techniques for creating elastin-like polypeptides. It allows for the expression and purification of elastin-like polypeptide (ELP) constructs that are poorly expressed or have very low transition temperatures. DNA concatemerization has been modified to reduce issues caused by methylation sensitivity and inefficient cloning. Linearization of the modified expression vector has been altered to greatly increase cleavage efficiency. The purification regimen is based upon using denaturing metal affinity chromatography to fully solubilize and, if necessary, pre-concentrate the target peptide before purification by inverse temperature cycling (ITC). This protocol has been used to express multiple leucine-containing elastin-like polypeptides, with final yields of 250-660 mg per liter of cells, depending on the specific construct. This was considerably greater than previously reported yields for similar ELPs. Due to the relative hydrophobicity of the tested constructs, even compared with commonly employed ELPs, conventional methods would not have been able to be purify these peptides.