Dual-responsive in situ gelling polymer matrix for tunable ketamine general anesthesia in experimental animals.

Animal experimentation is a critical part of the drug development process and pharmaceutical research. General anesthesia is one of the most common procedures. Careful administration and dosing of anesthetics ensure animal safety and study success. However, repeated injections are needed to maintain anesthesia, leading to adverse effects. Ketamine, a dissociative anesthetic, is commonly used for inducing anesthesia in animals and suffers from a short half-life requiring repeated dosing. Herein, we report a novel system for controlled anesthesia post-intraperitoneal administration. A polymer solution called "premix" was developed using two stimuli-responsive polymers, Pluronic (PF) and Carbopol (CP). As the premix was mixed with ketamine solution and injected, it underwent in situ gelation, hence controlling ketamine release and anesthesia. The PF and CP concentrations were optimized for the gelation temperature and viscosity upon mixing with the ketamine solution. The optimal premix/ketamine formulation (1.5:1) was liquid at room temperature and gel at physiological conditions with favorable mucoadhesion and rheology. Premix retarded the release of ketamine, translating to tunable anesthesia in vivo. Anesthesia duration and recovery were tunable per ketamine dose with minimal side effects. Therefore, we propose the implementation of PF/CP premix as a vehicle for general anesthesia in animals for optimal duration and effect.

Binary CuO\CoO nanoparticles inhibit biofilm formation and reduce the expression of papC and fimH genes in multidrug-resistant Klebsiella oxytoca.

BACKGROUND AND AIM: Binary copper-cobalt oxide nanoparticles (CuO\CoO NPs) are modern kinds of antimicrobials, which may get a lot of interest in clinical application. This study aimed to detect the effect of the binary CuO\CoO NPs on the expression of papC and fimH genes in multidrug-resistant (MDR) isolates of Klebsiella oxytoca to reduce medication time and improve outcomes. METHODS: Ten isolates of K. oxytoca were collected and identified by different conventional tests besides PCR. Antibiotic sensitivity and biofilm-forming ability were carried out. The harboring of papC and fimH genes was also detected. The effect of binary CuO\CoO nanoparticles on the expression of papC and fimH genes was investigated. RESULTS: Bacterial resistance against cefotaxime and gentamicin was the highest (100%), while the lowest percentage of resistance was to amikacin (30%). Nine of the ten bacterial isolates had the ability to form a biofilm with different capacities. MIC for binary CuO\CoO NPs was 2.5 µg/mL. Gene expression of papC and fimH was 8.5- and 9-fold lower using the NPs. CONCLUSION: Binary CuO\CoO NPs have a potential therapeutic effect against infections triggered by MDR K. oxytoca strains due to the NPs-related downregulation ability on the virulence genes of K. oxytoca.

Nanotechnology as a Promising Approach to Combat Multidrug Resistant Bacteria: A Comprehensive Review and Future Perspectives.

The wide spread of antibiotic resistance has been alarming in recent years and poses a serious global hazard to public health as it leads to millions of deaths all over the world. The wide spread of resistance and sharing resistance genes between different types of bacteria led to emergence of multidrug resistant (MDR) microorganisms. This problem is exacerbated when microorganisms create biofilms, which can boost bacterial resistance by up to 1000-fold and increase the emergence of MDR infections. The absence of novel and potent antimicrobial compounds is linked to the rise of multidrug resistance. This has sparked international efforts to develop new and improved antimicrobial agents as well as innovative and efficient techniques for antibiotic administration and targeting. There is an evolution in nanotechnology in recent years in treatment and prevention of the biofilm formation and MDR infection. The development of nanomaterial-based therapeutics, which could overcome current pathways linked to acquired drug resistance, is a hopeful strategy for treating difficult-to-treat bacterial infections. Additionally, nanoparticles' distinct size and physical characteristics enable them to target biofilms and treat resistant pathogens. This review highlights the current advances in nanotechnology to combat MDR and biofilm infection. In addition, it provides insight on development and mechanisms of antibiotic resistance, spread of MDR and XDR infection, and development of nanoparticles and mechanisms of their antibacterial activity. Moreover, this review considers the difference between free antibiotics and nanoantibiotics, and the synergistic effect of nanoantibiotics to combat planktonic bacteria, intracellular bacteria and biofilm. Finally, we will discuss the strength and limitations of the application of nanotechnology against bacterial infection and future perspectives.

Antibacterial and wound-healing potential of PLGA/spidroin nanoparticles: a study on earthworms as a human skin model.

Aim: The essential protein element of spider silk 'spidroin' was used to assess its impact on the wound-healing process. Methods: Spidroin nanoparticles (NPs) were prepared using poly(lactic-co-glycolic acid) polymer (PLGA/spidroin NPs) at different weight ratios (5:1, 10:1, 15:1) and were in vitro characterized. The optimized NPs were tested in vitro for release and antibacterial activity. To assess wound-healing effects, NPs were topically applied on surgically induced injuries in Allolobophora caliginosa earthworms as a robust human skin model. Results: Optimized NPs (173 ± 3 nm) revealed considerable antibacterial effect against Staphylococcus aureus and Escherichia coli. After 4 days of NPs application on wounds, macroscopical and histological examinations revealed a significant reduction in wound and re-epithelialization times. Conclusion: PLGA/spidroin NPs may represent a promising option for wound repair.

BCG Vaccine-Induced Trained Immunity and COVID-19: Protective or Bystander?

In late 2019, a new virulent coronavirus (CoV) emerged in Wuhan, China and was named as severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). This virus spread rapidly, causing the coronavirus disease-2019 (COVID-19) pandemic. Bacillus Calmette-Guérin (BCG) is a live attenuated tuberculosis (TB) vaccine, associated with induction of non-specific cross-protection against unrelated infections. This protection is a memory-like response in innate immune cells (trained immunity), which is caused by epigenetic reprogramming via histone modification in the regulatory elements of specific genes in monocytes. COVID-19 related epidemiological studies showed an inverse relationship between national BCG vaccination policies and COVID-19 incidence and death, suggesting that BCG may induce trained immunity that could confer some protection against SARS-CoV-2. As this pandemic has put most of Earth's population under quarantine, repurposing of the old, well-characterized BCG may ensure some protection against COVID-19. This review focuses on BCG-related cross-protection and acquisition of trained immunity, as well as the correlation between BCG vaccination and COVID-19 incidence and mortality.

Self-administrated vaginal 2% lidocaine in-situ gel for pain relief during copper intrauterine device insertion in women with previous caesarean delivery only: a randomised, double-blind placebo-controlled trial.

OBJECTIVE: To evaluate the analgesic effect of self-administered vaginal 2% lidocaine in-situ gel in pain relief during copper intrauterine device (IUD) insertion in women with previous caesarean delivery only. METHODS: A Randomised, double-blind, placebo-controlled trial (Clinicaltrials.gov: NCT03166111) included reproductive-aged women who previously delivered only by caesarean section (CS) requesting Copper IUD insertion. Eligible women were recruited and randomised (1:1) to lidocaine in-situ gel vs. placebo. Each woman was supplied by a syringe filled with five ml lidocaine or placebo in-situ gel to be self-administered vaginally ten minutes before insertion. The primary outcome was the difference in pain scores during IUD placement using a 10-cm Visual Analogue Scale (VAS). RESULTS: The final analysis included 216 women (n = 108 in each arm). Women in the Lidocaine in situ gel group were more likely to report statistically significant lower pain scores during vulsellum application, uterine sound placement, and during IUD placement [Mean difference (95%CI) = 2.04 (1.66-2.42), 2.62 (2.20-3.04), and 2.57 (2.12-3.01), respectively, p = 0.0001]. A significantly lower IUD insertion score indicating easier insertion was reported in the lidocaine group (p = 0.004). Similarly, the duration of IUD insertion was significantly shorter in the lidocaine group (p = 0.008). There was a higher level of satisfaction in the lidocaine group (5.92 vs. 3.34) in the placebo group (p = 0.0001). CONCLUSIONS: Self-administered vaginal lidocaine in-situ gel 10 min before copper IUD insertion is effective in pain reduction in women with previous caesarean delivery only.

Vaginal suppositories of cumin seeds essential oil for treatment of vaginal candidiasis: Formulation, in vitro, in vivo, and clinical evaluation.

Fungal infections by resistant Candida species continue to be a significant health problem. Novel antifungal agents such as essential oils of cumin seeds (EOCS) are tested against vulvovaginal candidiasis (VVC). The aim of this study was to develop coated polyethylene glycol (PEG) vaginal suppositories containing EOCS for treatment of VVC. PEG suppositories containing EOCS were prepared ppearance, weight variation, drug content, hardness, dissolution time, release, stability and anticandida activity were evaluated. Biocompatibility of selected formulation was tested in female rabbits, followed by clinical evaluation. Coated suppositories showed complete release of the oil after 30 min, in vitro anti-candida activity, enhanced stability and sufficient safety on the vaginal tissues of rabbits. Clinical results showed significant lower rates of vaginal itching, discharge and dyspareunia combined with negative cultures in 70% of patients, revealing efficacy of EOCS-containing vaginal suppositories for treatment of VVC.

Nanomedicine as a promising approach for diagnosis, treatment and prophylaxis against COVID-19.

The COVID-19 pandemic caused by the newly emerged severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) puts the world in an unprecedented crisis, leaving behind huge human losses and deep socioeconomic damages. Due to the lack of specific treatment against SARS-CoV-2, effective vaccines and antiviral agents are urgently needed to properly restrain the COVID-19 pandemic. Repositioned drugs such as remdesivir have revealed a promising clinical efficacy against COVID-19. Interestingly, nanomedicine as a promising therapeutic approach could effectively help win the battle between coronaviruses (CoVs) and host cells. This review discusses the potential therapeutic approaches, in addition to the contribution of nanomedicine against CoVs in the fields of vaccination, diagnosis and therapy.

Modulation of rifampicin-induced hepatotoxicity using poly(lactic-co-glycolic acid) nanoparticles: a study on rat and cell culture models.

Aim: Hepatotoxicity is the most serious adverse effect of rifampicin (RIF). We aimed to investigate the potential hepatoprotective effect of mannose-functionalized poly(lactic-co-glycolic acid)(PLGA)/RIF nanoparticles (NPs) in rats as a possible promising approach to minimize RIF-induced hepatotoxicity. Materials & methods: Mannose-functionalized PLGA/RIF NPs were fabricated and characterized in vitro, then the hepatoprotective effect of optimized NPs was studied on rat and cell culture models. Results: Following intraperitoneal administration of RIF NPs into rats, highly significant differences in levels of serum transaminases and oxidative stress markers, associated with significant differences in expression of Bax and Bcl-2 genes between NP- and free RIF-treated groups, revealing the hepatoprotective potential of NPs. Conclusion: RIF NPs may represent a promising therapeutic approach for tuberculosis via reducing dose frequency and consequently, RIF-induced hepatotoxicity.

Spidroin in carbopol-based gel promotes wound healing in earthworm's skin model.

Spider silk's regenerative, biocompatible, and antimicrobial properties render it a promising biomaterial for wound healing promotion. Spidroin as the main protein component of spider silks was used in this study to evaluate the potential effects on wound healing via topical application of novel spidroin-containing carbopol 934 (CP934) gel. Spidroin was extracted, formulated into CP934 gel, and characterized both in vitro and in vivo. Spidroin gel was translucent and brownish-yellow in color. An optimum viscosity was obtained at 0.6% CP934 at neutral pH. Optimized spidroin gel (0.6% CP934) effectively inhibited the growth of clinical bacterial isolates of methicillin-sensitive Staphylococcus aureus (MSSA), methicillin-resistant S. aureus (MRSA) and Escherichia coli at 440 µg/mL with MIC values of 0.98, 4.6, and 8.2 µg/mL, respectively. Optimized spidroin gel was evaluated for wound healing via topical application on wounds surgically induced in Allolobophora caliginosa earthworms used as a robust human skin model. After application for three consecutive days, dramatic reductions in wound closure and reepithelialization duration were observed macroscopically and via histological studies (light and electron microscopy) when compared with control. In conclusion, these results show that spidroin gel is a promising promoter for wound healing, and further studies would be directed toward investigating mechanisms underlying this effect.

Nanomedicine as a future therapeutic approach for Hepatitis C virus.

Hepatitis C virus (HCV) is not easily cleared from the human body and in most cases turned into chronic infection. This chronicity is a major cause of liver damage, cirrhosis and hepatocellular carcinoma. Therefore, immediate detection and treatment of HCV guarantees eradication of the virus and prevention of chronicity complications. Since discovery of HCV in 1989, several emerging treatments were developed such as polyethylene glycol(PEG)-ylated interferon/ribavirin, direct acting antivirals and host targeting antivirals. Despite the progress in anti-HCV therapy, there is still a pressing need of new approaches for affordable and effective drug delivery systems using nanomedicine. In this review, the contribution of nanoparticles as a promising delivery system for HCV immunizing, diagnostic and therapeutic agents are discussed.

Efficacy of ketoconazole gel-flakes in treatment of vaginal candidiasis: Formulation, in vitro and clinical evaluation.

Candida albicans, as the main causative fungus of vaginal candidiasis, is currently a global issue of concern due to its high prevalence, biofilm formation and emergence of resistance. Ketoconazole (KTZ), an antifungal drug, which has poor water-solubility and penetration capacity, is ineffective against deep-seated Candida infection. Considering these issues, this work aimed to develop a novel multifunctional carrier for KTZ via encapsulation of KTZ/ß-cyclodextrin (ß-CD) co-ground mixture into chitosan/gellan gum gel-flakes (threadlike and polygonal structures). Analytical studies revealed existence of electrostatic-derived complexes between negatively charged gellan gum and positively charged chitosan. Gel-flakes were then loaded in in situ gel of pluronic F-127 (PF-127). Based on gelation temperature (Tgel), viscosity and release studies; selected formulation was further evaluated, showing significant in vitro anti-candida activity. Despite reduced dosage regimen (50 mg/daily/three days), KTZ flakes in situ gel was as effective as Gynoconazol vaginal cream® (80 mg terconazole/daily/three days) in improving patient complaints and Candida eradication. Multifunctionality of KTZ carrier was based on efficient spreading and coating of the vagina due to free-flowing properties during application, flakes entanglement within folded vaginal epithelia, sustained release and increased penetration capacity of KTZ to reach deep-seated infections. In conclusion, flakes in situ gel could be considered as a highly promising KTZ delivery option for treatment of vaginal candidiasis.

Metoclopramide nanoparticles modulate immune response in a diabetic rat model: association with regulatory T cells and proinflammatory cytokines.

BACKGROUND: The inflammatory basis of diabetes mellitus directed the researchers' attention to the immune system for better management and prevention of complications. Metoclopramide (MCA; the only US Food and Drug Administration-approved for gastroparesis) has the ability to restore immune function through increasing prolactin secretion. This study aimed to test the effect of BSA/MCA nanoparticles (NPs) on modulating immune response. METHODS: BSA/MCA NPs were fabricated by desolvation and evaluated in vitro via measuring loading efficiency, particle size, and surface charge. The selected formula was further evaluated via differential scanning calorimetry and release behavior. Then, NPs were injected into rats (25 mg MCA/kg/week) for 3 weeks to be evaluated histopathologically and immunologically via measuring proinflammatory cytokines, such as IL1ß, IL6, and TNFα, in addition to measuring regulatory T-cell frequency. RESULTS: MCA was successfully loaded on BSA, achieving high encapsulation efficiency reaching 63±2%, particles size of 120-130 nm with good polydispersity, and a negative surface charge indicating that entire positively charged drug was encapsulated inside NPs. Differential scanning calorimetry thermography of selected NPs showed an obvious interaction between components and cross-linking of BSA molecules using glutaraldehyde, resulting in sustained release of MCA (around 50% within 3 days). MCA NPs significantly restored the immune response via decreasing proinflammatory cytokines and increasing regulatory T-cell frequency when compared to control and free MCA (drug not loaded in NPs)-treated groups. Histopathological examination of this MCA NPs-treated group did not show the characteristic lesions of diabetes, and apoptosis nearly disappeared. CONCLUSION: BSA/MCA NPs could be considered a new modality for treatment of gastro-paresis, in addition to management of diabetes itself and preventing its complications via an MCA-immunomodulatory effect.

Self-assembled tannic acid complexes for pH-responsive delivery of antibiotics: Role of drug-carrier interactions.

Self-assembled particles, based on non-covalent interactions, are attractive drug carriers with a relatively simple structure and easy preparation. Tannic acid (TA) is an anionic polyphenolic compound with a wide range of molecular interactions and diverse applications in drug delivery research. Here, we propose the use of TA complexes with cationic antibiotics as a new pH-responsive drug carrier of high drug loading and optimal stability. TA complexes were prepared with three water-soluble antibiotics; colistin sulfate (COL), gentamicin sulfate (GEN) and gatifloxacin (GAT). Complexes' size ranged from several-hundred nanometers to few microns. For selected particles, drug loading ranged from 30 to 36%. Importantly, we demonstrate the impact of drug-carrier interactions, studied via infrared spectroscopy and molecular modeling, on final complex stability and performance; the complexes resisted dissociation in presence of serum at physiological pH to variable degrees and showed different drug release profiles. However, all complexes dissociated upon medium acidification, releasing their drug payload and demonstrating expected antibacterial effect. These results demonstrate that TA/antibiotic self-assembled complexes represent an excellent carrier for pH-sensitive delivery of water-soluble drugs. In addition to system's simplicity and low cost, complexes were easily prepared with high drug loading and desirable pH-dependent association/dissociation profile.

Effect of topical glyceryl trinitrate cream on pain perception during intrauterine device insertion in multiparous women: A randomized double-blinded placebo-controlled study.

OBJECTIVE: Intrauterine contraceptive device (IUD) insertion-related pain presents a push beyond the decline of women to use IUD for family planning. We aimed to investigate the analgesic effect of glyceryl trinitrate cream (GTN) in reducing pain during IUD insertion. MATERIALS AND METHODS: We conducted a randomized double-blinded placebo-controlled study (NCT02708251, clinicaltrials.gov) in a tertiary University hospital. Reproductive-aged women requesting Copper IUD for contraception were considered. Eligible women for IUD insertion were randomized (1:1) to glyceryl trinitrate cream (GTN arm) or Placebo. Three minutes before IUD insertion, 1 ml of GTN cream or placebo was applied to the cervical lip at the planned tenaculum site, followed by 1 ml placed in the cervical canal up to the level of the internal os using a Q-tip applicator. Our outcomes were the participant's self-rated pain perception utilizing a 10-cm Visual Analogue Scale (VAS) during cervical tenaculum placement, uterine sound and IUD insertion, then 15 min post-procedure. RESULTS: 100 women were enrolled and randomized to GTN arm (n = 50) or placebo (n = 50). Women in the GTN arm reported lower VAS scores during tenaculum placement, sound and IUD insertion (median: 2 vs. 4, p < 0.0001; 2.5 vs. 4.5, p < 0.001;3 vs. 5.5, p < 0.0001, respectively). Higher ease of insertion score was also determined among GTN arm (mean ± SD: 6.9 ± 1.15 vs. 4.7 ± 1.38, p < 0.0001). Additionally, women in the GTN arm were more satisfied by the end of the insertion (92% vs. 74%, p = 0.003). CONCLUSION: Application of cervical GTN cream before IUD insertion seems to reduce the induced pain with subsequent easy insertion.

Dual-responsive lidocaine in situ gel reduces pain of intrauterine device insertion.

The most effective and safe contraceptive method, intrauterine devices (IUDs), is still underutilized due to the pain barrier during IUD insertion. Lidocaine, a well-known local anesthetic, can be used to relieve IUD insertion pain. This study aimed at formulation, in vitro, in vivo and clinical evaluation of a novel lidocaine dual-responsive in situ gel. Pluronic and Gelrite® were used as thermosenstive and ion-activated polymers, respectively. In situ gels containing 2% lidocaine, pluronics and/or Gelrite® were prepared. The optimized dual-responsive formula (F5) was clear, with 95% drug content, free flowing at room temperature and gel at vaginal temperature (Tgel of 28 °C). This optimized dual-responsive in situ gel was found to be superior to single-responsive one due to presence of Gelrite®, imparting resistance to dilution effect of simulated vaginal fluids. DSC thermograms revealed no interaction between formulation components. Biocompatibility study showed no degeneration, necrosis or inflammation. Optimized dual-responsive in situ gel was further evaluated for pain reduction efficiency via a pilot randomized, double-blinded, placebo-controlled clinical trial showing ease of self-administeration by patients and significant pain reduction induced at all steps of IUD insertion. In conclusion, lidocaine dual-responsive in situ gel can be effectively used in prevention of pain during IUD insertion.

Surface functionalization of polymeric nanoparticles for tumor drug delivery: approaches and challenges.

INTRODUCTION: For years, injectable polymeric nanoparticles (NPs) have been developed for delivering therapeutic agents to the tumors. Frequently, NPs surface have been modified with different moieties and/or ligands to impart stealth effect and/or elicit specific cellular interactions, both known to dramatically affect the in vivo fate and efficacy of these NPs. Areas covered: We discuss different types of ligands and molecules used for surface functionalization of polymeric NPs for tumor drug delivery. First, we summarize methods used through the literature for surface modification of polymeric NPs, then discuss challenges that face researchers either in decorating NPs with desired surface functionalities, characterizing functionalized surfaces or achieving intended cellular interactions and in vivo effects. Expert opinion: Modification of NP surfaces dramatically alters their behavior and favorably enhances their therapeutic efficacy. Choice of surface ligand/functionality should be based on intended therapeutic outcomes, taking into consideration the potential of clinical translation and scale up of the developed systems.