Multifunctional polysaccharide/metal/polyphenol double-crosslinked hydrogel for infected wound.

Bacterial-infected wounds present a significant challenge in the medical field, posing a severe threat to public health. Traditional wound dressings have limited efficacy in treating bacterial-infected wounds, and antibiotics suffer from cytotoxicity and drug resistance. Consequently, an urgent requirement exists for developing multifunctional wound dressings capable of providing superior antimicrobial activity and expediting wound repair. In recent years, chitosan-based natural polysaccharide hydrogels have garnered attention for their biocompatibility, antimicrobial properties, and ability to aid in hemostasis. This study presents the development of a multi-functional, bi-dynamic network hydrogel for the treatment of wounds infected with bacteria. The hydrogel consists of a backbone of chitosan grafted with chlorogenic acid (CA-ECS), oxidized pullulan polysaccharides (OP), and zinc ions (Zn2+). The CA-ECS/OP/Zn2+ hydrogel displayed strong adhesion, good injectability, and high mechanical strength and was biodegradable and biocompatible. Furthermore, adding Zn2+ and CA enhanced the hydrogel's mechanical properties and antioxidant and antimicrobial activities. In a rat model of full-thickness skin wounds infected with S. aureus, the CA-ECS/OP/Zn2+ hydrogel demonstrated great anti-inflammatory, angiogenic, and folliculogenic properties, resulting in accelerated wound healing. The CA-ECS/OP/Zn2+ hydrogel has great potential for treating bacterial-infected wounds.

Pharmacokinetics in Penguins Compared to Other Avian Species: A Review of Enrofloxacin and Voriconazole.

Australasia is home to unique and endangered avian species. Drug administration to this group of animal patients for prophylaxis and treatment is challenging from a number of different perspectives. A key limitation for optimal drug dosing in birds is the lack of published pharmacokinetic studies to guide dose requirements. The aim of this review was to systematically investigate published literature on pharmacokinetics in penguin species and compare that with the pharmacokinetics of other avian species with a focus on two drugs: enrofloxacin and voriconazole. The review was conducted following PRISMA guidelines. A systematic literature search was performed in Pubmed, Embase, Scopus, and Web of Science databases. A key finding is that penguin pharmacokinetics differs from other avian species, with weight-adjusted AUC and Cmax values higher than most other avian species (e.g., for enrofloxacin, the AUC in the African penguin is 85.7 µg h/mL, which is more than double the other bird species). Doses for some avian species may be successfully extrapolated from other avian species; however, it appears important to consider factors other than just body weight (e.g., clearance mechanism and drug physicochemical characteristics). Consequently, there is an important need for robust pharmacokinetic data in wildlife species to ensure optimal therapy for this special group of patients. As part of this review, we identify key aspects that should be considered when estimating dose in species for which there is limited pharmacokinetic information available.

Pharmacists in zoos? A qualitative study investigating the potential for pharmacist involvement in wildlife health care in Aotearoa, New Zealand.

BACKGROUND: The importance of wildlife health has been critically emphasized by the current global pandemic. Pharmacists play a valuable role in the health care of companion animals and livestock; however, their involvement in exotic animal health is largely unexplored. OBJECTIVES: This project consulted with zoo vets in New Zealand and investigated their practices around prescribing and dispensing of medicines to explore the opportunities for the involvement of pharmacists. METHODS: A mixed methods approach was used where data were initially collected through an online survey distributed to 26 veterinarians and animal keepers working in zoos, wildlife parks, and sanctuaries. An optional semistructured interview followed the survey. RESULTS: The facilities surveyed housed New Zealand native animal species and 85% also housed exotic animals. Veterinarians dispensed 75% of medicines at their animal facility, whereas the remaining 25% were dispensed by veterinary nurses. On average, 5-10 medications were dispensed at each animal facility per day. Common medicines dispensed were antibiotics, pain relievers, and antifungals. Most respondents felt that they could benefit from working alongside pharmacists in veterinary care. Compounding, access to medicines and identification of tailored formulations were identified as areas where collaboration would be valued. Limitations in the knowledge of pharmacists in animal medicine were distinguished as an area enhancement to assist in collaborative relationships. CONCLUSIONS: There are opportunities for the skills of pharmacists to be incorporated into the care of animals in zoos and wildlife parks in New Zealand. Strengthening the pharmacist-veterinarian relationship can enhance the health outcomes of animals in animal facilities through this interprofessional interaction.

Pharmaceutics for free-ranging wildlife: Case studies to illustrate considerations and future prospects.

Wildlife medicine is a specialised division of veterinary medicine that is concerned with patients that are physiologically very diverse with similarly diverse life histories. The medicines to be delivered to wildlife parallel those used in other areas of veterinary medicine and human medicine, however species-specific information on drug administration is lacking for wildlife species. Currently there are numerous threats of extinction to wildlife globally due to climate change and habitat destruction. The COVID-19 pandemic has also made us acutely aware of the important link between human health and wildlife health and how zoonotic diseases can cause devastating impacts globally. Consequently, the ability to effectively treat this group of animals with therapeutic compounds is becoming increasingly more critical. Importantly, delivery of therapeutics to wildlife is a particular challenge that must be overcome. The objective is to highlight the area of wildlife therapeutics as an emerging field by presenting case studies to illustrate the opportunities for engagement of pharmaceutical scientists in this fascinating frontier of research. The case studies included are avian malaria in yellow-eyed penguins, transmissible cancers in Tasmanian devils, and the vaccination of wildlife for the control of SARS-Cov-2 transmission.

Modeling the interaction of polymeric nanoparticles functionalized with cell penetrating peptides at the nano-bio interface.

The interaction of nanoparticles with Caco-2 monolayers in cell culture underpins our predictions of the uptake of nanoformulations in vivo for drug delivery. Cell-penetrating peptides (CPP), such as oligoarginine, are currently of interest to enhance cellular uptake of bioactives and nanoparticles. This paper assesses the cellular association of poly(ethyl-cyanoacrylate) nanoparticles functionalized with di-arginine-histidine (RRH) in a Caco-2 cell model. We applied a computational model of particokinetics, In vitro Sedimentation, Diffusion and Dosimetry (ISDD) to predict the accumulation of nanoparticles on the cell surface. An important finding is that the proportion of nanoparticles associated with cells was less than 5 %. This has important implications for interpreting nanoparticle uptake in vitro. RRH-decoration does not appear to alter nanoparticle deposition, but increases association of nanoparticles with Caco-2 cells. Immediate deposition of nanoparticles on the cell surface was apparent and similar between formulations, but underestimated by the ISDD model. Key to understanding the nano-bio interface for drug delivery, nanoparticles that reach the cells were not necessarily absorbed by them, but can become detached. This variable of nanoparticle release from cells was incorporated into a new mathematical model presented here.

Improving Antibacterial Activity of a HtrA Protease Inhibitor JO146 against Helicobacter pylori: A Novel Approach Using Microfluidics-Engineered PLGA Nanoparticles.

Nanoparticle drug delivery systems have emerged as a promising strategy for overcoming limitations of antimicrobial drugs such as stability, bioavailability, and insufficient exposure to the hard-to-reach bacterial drug targets. Although size is a vital colloidal feature of nanoparticles that governs biological interactions, the absence of well-defined size control technology has hampered the investigation of optimal nanoparticle size for targeting bacterial cells. Previously, we identified a lead antichlamydial compound JO146 against the high temperature requirement A (HtrA) protease, a promising antibacterial target involved in protein quality control and virulence. Here, we reveal that JO146 was active against Helicobacter pylori with a minimum bactericidal concentration of 18.8-75.2 µg/mL. Microfluidic technology using a design of experiments approach was utilized to formulate JO146-loaded poly(lactic-co-glycolic) acid nanoparticles and explore the effect of the nanoparticle size on drug delivery. JO146-loaded nanoparticles of three different sizes (90, 150, and 220 nm) were formulated with uniform particle size distribution and drug encapsulation efficiency of up to 25%. In in vitro microdilution inhibition assays, 90 nm nanoparticles improved the minimum bactericidal concentration of JO146 two-fold against H. pylori compared to the free drug alone, highlighting that controlled engineering of nanoparticle size is important in drug delivery optimization.

Calcium pectinate and hyaluronic acid modified lactoferrin nanoparticles loaded rhein with dual-targeting for ulcerative colitis treatment.

Herein, dual-bioresponsive of Rhein (RH) in promoting colonic mucous damage repair and controlling inflammatory reactions were combined by the dual-targeting (intestinal epithelial cells and macrophages) oral nano delivery strategy for effective therapy of ulcerative colitis (UC). Briefly, two carbohydrates, calcium pectinate (CP) and hyaluronic acid (HA) were used to modify lactoferrin (LF) nanoparticles (NPs) to encapsulate RH (CP/HA/RH-NPs). CP layer make CP/HA/RH-NPs more stable and protect against the destructive effects of the gastrointestinal environment and then release HA/RH-NPs to colon lesion site. Cellular uptake evaluation confirmed that NPs could specifically target and enhance the uptake rate via LF and HA ligands. in vivo experiments revealed that CP/HA/RH-NPs significantly alleviated inflammation by inhibiting the TLR4/MyD88/NF-κB signaling pathway and accelerated colonic healing. Importantly, with the help of CP, this study was the first to attempt for LF as a targeting nanomaterial in UC treatment and offers a promising food-based nanodrug in anti-UC.

Interactions of Cell-Penetrating Peptide-Modified Nanoparticles with Cells Evaluated Using Single Particle Tracking.

Cell-penetrating peptides (CPPs) are known to interact with cell membranes and by doing so enhance cellular interaction and subsequent cellular internalization of nanoparticles. Yet, the early events of membrane interactions are still not elucidated, which is the aim of the present work. Surface conjugation of polymeric nanoparticles with cationic CPPs of different architecture (short, long linear, and branched) influences the surface properties, especially the charge of the nanoparticles, and therefore provides the possibility of increased electrostatic interactions between nanoparticles with the cell membrane. In this study, the physicochemical properties of CPP-tagged poly(lactic-co-glycolic acid) (PLGA) nanoparticles were characterized, and nanoparticle-cell interactions were investigated in HeLa cells. With the commonly applied methods of flow cytometry as well as confocal laser scanning microscopy, low and similar levels of nanoparticle association were detected for the PLGA and CPP-tagged PLGA nanoparticles with the cell membrane. However, single particle tracking of CPP-tagged PLGA nanoparticles allowed direct observation of the interactions of individual nanoparticles with cells and consequently elucidated the impact that the CPP architecture on the nanoparticle surface can have. Interestingly, the results revealed that nanoparticles with the branched CPP architecture on the surface displayed decreased diffusion modes likely due to increased interactions with the cell membrane when compared to the other nanoparticles investigated. It is anticipated that single particle approaches like the one used here can be widely employed to reveal currently unresolved characteristics of nanoparticle-cell interaction and aid in the design of improved surface-modified nanoparticles for efficient delivery of therapeutics.

Chlorogenic Acid Supplementation Benefits Zebrafish Embryos Exposed to Auranofin.

Antioxidant supplementation may potentially be beneficial for embryonic development to reduce complications associated with increased levels of oxidative stress. Chlorogenic acid, one of the key polyphenolic antioxidants in S. oleraceus, was evaluated for potential protective effects during embryonic development of zebrafish exposed to the teratogen auranofin. Zebrafish embryos were transiently exposed to auranofin to induce developmental abnormalities. Phenotypic abnormalities were scored based on their severity at day 5 post-fertilization. The embryos supplemented with 250 µM chlorogenic acid showed a significantly lower score in phenotypic abnormalities compared to non-supplemented embryos after auranofin exposure. Therefore, supplementation with a low dose of chlorogenic acid showed a protective effect from auranofin-induced deformities and encouraged normal growth in zebrafish embryos. This study provides further support for the potential of using antioxidant supplementation during embryonic development for protection against malformation.

Nanoemulsion structure and food matrix determine the gastrointestinal fate and in vivo bioavailability of coenzyme Q10.

In this work, we sought to incorporate coenzyme Q10-loaded nanoemulsions into a food system and to understand the impact of food digestion on the in vivo bioavailability of this bioactive compound. We selected octenyl succinic anhydride modified starch as emulsifier to prepare the nanoemulsions (with approximately 200 nm droplet diameter) after comparing with two other food-grade surfactants (whey protein isolate and lecithin) in terms of their colloidal stability during simulated gastrointestinal digestion. The change in ζ-potential revealed that the initial emulsifier might be partially replaced by bile salts under intestinal conditions, and the mixed micelles formed after digestion showed an apparent permeability coefficient of 4.79 × 10-6 cm/s in a rat intestinal epithelial cell line, without compromising the trans-epithelial electrical resistance. In a second step, a high protein beverage that incorporated the coenzyme Q10-loaded nanoemulsion was developed in a food pilot plant. The beverage had a particle size of D4,3 = 18 µm and D3,2 = 2.5 µm, corresponding to its different components. The changes in particle morphology and size distribution were analysed to understand the behaviour of this beverage during simulated gastrointestinal digestion. When coenzyme Q10 was encapsulated into the nanoemulsions and the beverage, its bioavailability in vivo increased 1.8- and 2.8-fold respectively, compared with coenzyme Q10 dissolved in oil. The higher coenzyme Q10 bioavailability in the beverage was probably because of a significantly higher level of lipolytic activity found for beverage than for nanoemulsions during gastrointestinal digestion. These results show the potential of using natural food materials to generate formulations to improve the bioavailability of bioactive compounds. More importantly, we highlight the influence of food digestion (i.e. lipolysis) on the absorption of hydrophobic bioactive components and suggest that food systems can be utilised as a dosage form to further enhance oral bioavailability.

Utilization of Microfluidics for the Preparation of Polymeric Nanoparticles for the Antioxidant Rutin: A Comparison with Bulk Production.

OBJECTIVE: To compare the characteristics of rutin-loaded PLGA (poly(lactic-coglycolic acid)) nanoparticles prepared using a single emulsion evaporation method (bulk method) and a nanoprecipitation method using microfluidics. METHODS: Rutin-loaded PLGA nanoparticles were produced using different methods and characterized for size, zeta potential, entrapment efficiency (EE) and drug loading (DL). A design of experiments approach was used to identify the effect of method parameters to optimize the formulation. DSC was used to investigate the solid-state characteristics of rutin and PLGA and identify any interactions in the rutin-loaded PLGA nanoparticles. The release of rutin from PLGA nanoparticles was examined in biorelevant media and phosphate buffer (PBS). RESULTS: The optimal formulation of rutin-loaded PLGA nanoparticles produced using a microfluidics method resulted in a higher entrapment efficiency of 34 ± 2% and a smaller size of 123 ± 4 nm compared to a bulk method (EE 27 ± 1%, size 179 ± 13 nm). The solidstate of rutin and PLGA changed from crystalline to amorphous with the preparation of rutin- loaded PLGA nanoparticles. More importantly, using microfluidics, rutin released faster from rutin-loaded PLGA nanoparticles in biorelevant media and PBS with higher burst release compared to the rutin release from the nanoparticles prepared by using the bulk method. CONCLUSION: Rutin can be encapsulated in nanoparticles formulated with different methods with mean sizes of less than 200 nm. Microfluidics produced more uniform rutin-loaded PLGA nanoparticles with a higher EE, DL and faster release compared to a bulk production method.

Microfluidics for the Production of Nanomedicines: Considerations for Polymer and Lipid-based Systems.

BACKGROUND: Microfluidics is becoming increasingly of interest as a superior technique for the synthesis of nanoparticles, particularly for their use in nanomedicine. In microfluidics, small volumes of liquid reagents are rapidly mixed in a microchannel in a highly controlled manner to form nanoparticles with tunable and reproducible structure that can be tailored for drug delivery. Both polymer and lipid-based nanoparticles are utilized in nanomedicine and both are amenable to preparation by microfluidic approaches. AIM: Therefore, the purpose of this review is to collect the current state of knowledge on the microfluidic preparation of polymeric and lipid nanoparticles for pharmaceutical applications, including descriptions of the main synthesis modalities. Of special interest are the mechanisms involved in nanoparticle formation and the options for surface functionalisation to enhance cellular interactions. CONCLUSION: The review will conclude with the identification of key considerations for the production of polymeric and lipid nanoparticles using microfluidic approaches.

Comparison of bulk and microfluidics methods for the formulation of poly-lactic-co-glycolic acid (PLGA) nanoparticles modified with cell-penetrating peptides of different architectures.

The efficient and reproducible production of nanoparticles using bulk nanoprecipitation methods is still challenging because of low batch to batch reproducibility. Here, we optimize a bulk nanoprecipitation method using design of experiments and translate to a microfluidic device to formulate surface-modified poly-lactic-co-glycolic (PLGA) nanoparticles. Cell-penetrating peptides (CPPs) with a short, long linear or branched architecture were used for the surface modification of PLGA nanoparticles. The microfluidics method was more time efficient than the bulk nanoprecipitation method and allowed the formulation of uniform PLGA nanoparticles with a size of 150 nm, a polydispersity index below 0.150 and with better reproducibility in comparison to the bulk nanoprecipitation method. After surface modification the size of CPP-tagged PLGA nanoparticles increased to 160-180 nm and the surface charge of the CPP-tagged PLGA nanoparticles varied between -24 mV and +3 mV, depending on the architecture and concentration of the conjugated CPP. Covalent attachment of CPPs to the PLGA polymer was confirmed with FTIR by identifying the formation of an amide bond. The conjugation efficiency of CPPs to the polymeric PLGA nanoparticles was between 32 and 80%. The development and design of reproducible nanoformulations with tuneable surface properties is crucial to understand interactions at the nano-bio interface.

The distribution of cell-penetrating peptides on polymeric nanoparticles prepared using microfluidics and elucidated with small angle X-ray scattering.

HYPOTHESIS: The distribution of three cell-penetrating peptides (CPPs) with different architectures (short, long linear and branched) on poly(lactic-co-glycolic) acid (PLGA) nanoparticles depends on the conjugation approach. Here, we explore the utilization of a zero-length crosslinking reaction for the covalent attachment of CPPs to PLGA nanoparticles and the translation of the reaction into a microfluidic platform. EXPERIMENTS: A microfluidic device with a staggered herringbone mixer was used for the formulation of CPP-tagged PLGA nanoparticles. CPP-tagged PLGA nanoparticles were labeled with gold nanoparticles (AuNPs) and transmission electron microscopy (TEM) and small angle X-ray scattering (SAXS) were used to elucidate the distribution of CPPs. FINDINGS: The SAXS scattering profiles for the CPP-tagged PLGA nanoparticles prepared with the in situ microfluidics conjugation approach indicated a distribution of the Au-labeled CPPs throughout the PLGA nanoparticles. For the post-microfluidics conjugation approach, the SAXS scattering profiles did not show the feature of the Au-labeled CPPs distributed throughout the PLGA nanoparticles and an arrangement of the Au-labeled CPP on the surface was support by TEM micrographs. The distribution of the CPPs was highly dependent on the conjugation approach and was not influenced by the architecture of the CPPs. The results provided insight for the rational design of CPP-tagged PLGA nanoparticles using microfluidics.

Aniracetam does not improve working memory in neurologically healthy pigeons.

Understanding the effects of cognitive enhancing drugs is an important area of research. Much of the research, however, has focused on restoring memory following some sort of disruption to the brain, such as damage or injections of scopolamine. Aniracetam is a positive AMPA-receptor modulator that has shown promise for improving memory under conditions when the brain has been damaged, but its effectiveness in improving memory in neurologically healthy subjects is unclear. The aim of the present study was to examine the effects of aniracetam (100mg/kg and 200 mg/kg) on short-term memory in "neurologically healthy" pigeons. Pigeons were administered aniracetam via either intramuscular injection or orally, either 30 or 60 minutes prior to testing on a delayed matching-to-sample task. Aniracetam had no effect on the pigeons' memory performance, nor did it affect response latency. These findings add to the growing evidence that, while effective at improving memory function in models of impaired memory, aniracetam has no effect in improving memory in healthy organisms.

Designing a Formulation of the Nootropic Drug Aniracetam Using 2-Hydroxypropyl-ß-Cyclodextrin Suitable for Parenteral Administration.

The nootropic drug aniracetam is greatly limited in its application by low aqueous solubility and a poor oral bioavailability. The primary aim of this study was to design a parenteral formulation of aniracetam that can be administered intravenously. Complexation of aniracetam with 2-hydroxypropyl-ß-cyclodextrin (HP-ß-CD) was investigated as a strategy to enhance solubility. A phase solubility analysis was performed to quantify the extent of improvement. An 819% increase in the solubility of aniracetam was obtained, reaching 36.44 mg/mL. This marked increase enables aniracetam to exist in an aqueous solvent at levels sufficient for parenteral dosing. A stability test was then devised using a design of experiment approach. The aniracetam-HP-ß-CD formulation was subjected to different relative humidity and temperature and cyclodextrin concentrations over a 12-week period. Key changes in FTIR vibrational frequencies suggest the benzene moiety of aniracetam was introduced into the hydrophobic cavity of HP-ß-CD. These results are highly supportive of the formation of a predictable 1:1 molar stoichiometric inclusion complex, explaining the improvement seen in physiochemical properties of aniracetam following formulation with HP-ß-CD. This novel formulation of aniracetam suitable for parenteral administration will have utility in future studies to further elucidate the pharmacokinetics of this drug.

Are phytosomes a superior nanodelivery system for the antioxidant rutin?

Rutin, a strong antioxidant, has been implicated in the prevention of liver inflammation. However, low solubility and permeability through the gut wall limit development of rutin as a therapeutic agent for oral administration. Phytosomes are described as lipid nanocarriers with a complexation between the phospholipid headgroups and entrapped phytochemicals. The aim of this research was to compare the structure of rutin liposomes to rutin phytosomes. FT-IR, DSC and NMR were employed to investigate the presence of any molecular interactions between the formulation components. The FT-IR spectra showed that a new -OH bond had formed in the rutin phytosomes, suggesting the formation of a molecular complex. 31P NMR experiments revealed that the DPPC molecule is altered when formulated as liposomes but that these changes were greater for samples from the phytosome formulation. DSC data revealed that when rutin was added to DPPC there was a significant shift in the transition temperature of DPPC. Further, the shift was greater in the THF solvent used to produce phytosomes compared to CHCl3 used to produce liposomes. 1H NMR spectra of the phytosome samples indicated three additional peaks that were greater than in the liposome formulation. ROESY NMR spectra provided evidence supporting the interaction between rutin and DPPC in both liposomes and phytosomes. The apparent differences in molecular interaction between liposomes and phytosomes did not however impact rutin release in biorelevant media or during in vitro small intestinal lipolysis.

Poloxamer 407-chitosan grafted thermoresponsive hydrogels achieve synchronous and sustained release of antigen and adjuvant from single-shot vaccines.

Sustained-release vaccine delivery systems may enhance the immunogenicity of subunit vaccines and reduce the need for multiple vaccinations. The aim of this study was to develop a thermoresponsive hydrogel using poloxamer 407-chitosan (CP) grafted copolymer as a delivery system for single-shot sustained-release vaccines. The CP copolymer was synthesized using 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide and N-hydroxysuccinimide chemistry. The CP copolymer was a free flowing solution at ambient temperature and transformed rapidly into a gel at body temperature. The hydrogels were loaded with vaccine antigen and adjuvants or the vaccine components were encapsulated in poly (lactic-co-glycolic acid) nanoparticles in order to ensure synchronous release. The CP hydrogels were stable for up to 18 days in vitro. Release of both nanoparticles and the individual components was complete, with release of the individual components being modulated by incorporation into nanoparticles. In vivo, a single dose of CP hydrogel vaccine induced strong, long lasting, cellular and humoral responses that could protect against the development of tumors in a murine melanoma model.