Isotonic sodium bicarbonate-triggered emodin release from borate stabilized emodin nanoparticles-loaded polymeric microgel films

Antimicrobial films fabricated with myricetin nanoparticles and chitosan derivation microgels for killing pathogenic bacteria in drinking water

Pathogenic bacteria in drinking water threaten human health and life. In the work, antimicrobial films composed of myricetin@tannic acid (My@TA) nanoparticles (NPs) and chitosan derivation microgels were developed to kill pathogenic bacteria in drinking water. Hydrophobic My was first made into water soluble My@TA NPs using a solvent exchange method with TA as stabilizer. Polymeric microgels of carboxymethyl chitosan (CMCS)/hydroxypropyltrimethyl ammonium chloride chitosan (HACC) were then fabricated with a blending method. CMCS&HACC/My@TA multilayer films were further deposited on the internal surface of PET bottles by using a layer-by-layer (LbL) assembly technique. The PET bottles coated with the films could effectively kill pathogenic bacteria in water such as S. aureus, E. coli, Staphylococcus epidermidis, Pseudomonas fluorescens, Listeria monocytogenes and methicillin resistant Staphylococcus aureus (MRSA). In addition, CMCS&HACC/My@TA films displayed good antioxidant activity, water resistance, and in vivo biocompatibility with heart, liver, spleen, lung and kidney organs. We believe that the container coated with CMCS&HACC/My@TA films can be applied to prevent microbial contamination of drinking water.

Bandage modified with antibacterial films of quaternized chitosan & sodium carboxymethyl cellulose microgels/baicalein nanoparticles for accelerating infected wound healing

Wound dressings capable of sterilizing pathogenic bacteria and scavenging free radicals are important to inhibit bacterial invasion and accelerate wound healing. The target of this work is to develop an antibacterial dressing by modifying bandages with films composed of biological macromolecule microgels and baicalein@tannic acid (Bai@TA) nanoparticles (NPs). Firstly, hydrophobic Bai was made into water soluble Bai@TA NPs using a solvent exchange method with TA as stabilizer. Polymeric microgels of sodium carboxymethyl cellulose (CMC)&hydroxypropyltrimethyl ammonium chloride chitosan (HACC) were then prepared by a simple blending method. Further, CMC&HACC/Bai@TA multilayer films were deposited on medical bandages by using a layer-by-layer assembly technique to obtain an antibacterial dressing. The as-prepared dressings showed great antibacterial ability against E. coli, S. aureus and methicillin resistant Staphylococcus aureus (MRSA), excellent antioxidant activity and good biological safety. In addition, compared to conventional medical bandages, the dressings could efficaciously diminish inflammation in the wound, accelerate skin regeneration and functional restoration, and promote the in vivo healing speed of full-thickness skin wounds infected by MRSA. We believe that as a low-cost but effective wound dressing, the antibacterial bandage modified with CMC&HACC/Bai@TA films has potentials to replace traditional dressings in the clinical management of infected wounds.

A mannitol-modified emodin nano-drug restores the intestinal barrier function and alleviates inflammation in a mouse model of DSS-induced ulcerative colitis

BACKGROUND

Ulcerative colitis (UC) is an inflammatory disease of the colon that is characterized by mucosal ulcers. Given its increasing prevalence worldwide, it is imperative to develop safe and effective drugs for treating UC. Emodin, a natural anthraquinone derivative present in various medicinal herbs, has demonstrated therapeutic effects against UC. However, low bioavailability due to poor water solubility limits its clinical applications.

METHODS

Emodin-borate nanoparticles (EmB) were synthesized to improve drug solubility, and they modified with oligomeric mannitol into microgels (EmB-MO) for targeted delivery to intestinal macrophages that express mannose receptors. UC was induced in a mouse model using dextran sulfate sodium (DSS), and different drug formulations were administered to the mice via drinking water. The levels of inflammation-related factors in the colon tissues and fecal matter were measured using enzyme-linked immunosorbent assay. Intestinal permeability was evaluated using fluorescein isothiocyanate dextran. HE staining, in vivo imaging, real-time PCR, and western blotting were performed to assess intestinal barrier dysfunction.

RESULTS

Both EmB and EmB-MO markedly alleviated the symptoms of UC, including body weight loss, stool inconsistency, and bloody stools and restored the levels of pro- and anti-inflammatory cytokines. However, the therapeutic effects of EmB-MO on the macroscopic and immunological indices were stronger than those of EmB and similar to those of 5-aminosalicylic acid. Furthermore, EmB-MO selectively accumulated in the inflamed colon epithelium and restored the levels of the gut barrier proteins such as ZO-1 and Occludin.

CONCLUSIONS

EmB-MO encapsulation significantly improved water solubility, which translated to greater therapeutic effects on the immune balance and gut barrier function in mice with DSS-induced UC. Our findings provide novel insights into developing emodin-derived drugs for the management of UC.

Optimization of Lipid Nanoformulations for Effective mRNA Delivery

Introduction

Since the coronavirus disease 2019 (COVID-19) pandemic, the value of mRNA vaccine has been widely recognized worldwide. Messenger RNA (mRNA) therapy platform provides a promising alternative to DNA delivery in non-viral gene therapy. Lipid nanoparticles (LNPs), as effective mRNA delivery carriers, have been highly valued by the pharmaceutical industry, and many LNPs have entered clinical trials.

Methods

We developed an ideal lipid nanoformulation, named LNP3, composed of 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP), 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE) and cholesterol, and observed its release efficiency, sustained release, organ specific targeting and thermal stability.

Results

In vitro studies showed that the transfection efficiency of LNP3 was higher than that of LNPs composed of DOTAP-DOPE and DOTAP-cholesterol. The positive to negative charge ratio of LNPs is a determinant of mRNA transfer efficiency in different cell lines. We noted that the buffer affected the packaging of mRNA LNPs and identified sodium potassium magnesium calcium and glucose solution (SPMCG) as a favorable buffer formulation. LNP3 suspension can be lyophilized into a thermally stable formulation to maintain activity after rehydration both in vitro and in vivo. Finally, LNP3 showed sustained release and organ specific targeting.

Conclusion

We have developed an ideal lipid nanoformulation composed of DOTAP, DOPE and cholesterol for effective mRNA delivery.

β-1,3-d-Glucan based yeast cell wall system loaded emodin with dual-targeting layers for ulcerative colitis treatment

Herein, a β-1,3-d-glucan based microcarrier, yeast cell wall microparticles (YPs), was used to develop a food-source-based nano-in-micro oral delivery system for ulcerative colitis (UC) treatment. Briefly, lactoferrin (Lf), which targets intestinal epithelial cells, was used to encapsulate emodin (EMO) to form nanoparticles (EMO-NPs), and then loaded into YPs with the natural macrophages targeting ability, forming a final formula with two outer-inner targeting layers (EMO-NYPs). These dual-targeting strategy could enhance the dual-effects of EMO in anti-inflammatory and mucosal repair effects respectively. As expected, cell uptake assessment confirmed that EMO-NPs and EMO-NYPs could target on the Lf and dection-1 receptors on the membranes of Caco-2 cells and macrophages, respectively. Importantly, EMO-NYPs showed the best anti-UC effects compared to EMO-NPs and free EMO, by inhibiting NF-κB pathway to anti-inflammation and promoting intestinal mucosa repair via MLCK/pMLC2 pathway. The results show that EMO-NYPs are a promising food-based oral delivery system in anti-UC.

Natural Products for the Management of Castration-Resistant Prostate Cancer: Special Focus on Nanoparticles Based Studies

Prostate cancer is the most common type of cancer among men and the second most frequent cause of cancer-related mortality around the world. The progression of advanced prostate cancer to castration-resistant prostate cancer (CRPC) plays a major role in disease-associated morbidity and mortality, posing a significant therapeutic challenge. Resistance has been associated with the activation of androgen receptors via several mechanisms, including alternative dehydroepiandrosterone biosynthetic pathways, other androgen receptor activator molecules, oncogenes, and carcinogenic signaling pathways. Tumor microenvironment plays a critical role not only in the cancer progression but also in the drug resistance. Numerous natural products have shown major potential against particular or multiple resistance pathways as shown by in vitro and in vivo studies. However, their efficacy in clinical trials has been undermined by their unfavorable pharmacological properties (hydrophobic molecules, instability, low pharmacokinetic profile, poor water solubility, and high excretion rate). Nanoparticle formulations can provide a way out of the stalemate, employing targeted drug delivery, improved pharmacokinetic drug profile, and transportation of diagnostic and therapeutic agents via otherwise impermeable biological barriers. This review compiles the available evidence regarding the use of natural products for the management of CRPC with a focus on nanoparticle formulations. PubMed and Google Scholar search engines were used for preclinical studies, while ClinicalTrials.gov and PubMed were searched for clinical studies. The results of our study suggest the efficacy of natural compounds such as curcumin, resveratrol, apigenin, quercetin, fisetin, luteolin, kaempferol, genistein, berberine, ursolic acid, eugenol, gingerol, and ellagic acid against several mechanisms leading to castration resistance in preclinical studies, but fail to set the disease under control in clinical studies. Nanoparticle formulations of curcumin and quercetin seem to increase their potential in clinical settings. Using nanoparticles based on betulinic acid, capsaicin, sintokamide A, niphatenones A and B, as well as atraric acid seems promising but needs to be verified with preclinical and clinical studies.

Antibacterial, antioxidant and biocompatible nanosized quercetin-PVA xerogel films for wound dressing

Topical use of antimicrobial agents to treat wounds to inhibit bacterial invasion and facilitate wound healing is an effective strategy. In this work, an antibacterial xerogel film for potential applications in wound dressings was developed. First, a natural antibacterial agent, quercetin (Qu), was made into water-soluble quercetin-borate (QuB) nanoparticles by merging a solvent exchange method with the borate esterification reaction. QuB nanoparticles were then employed as the cross-linking agent to achieve gelation of poly(vinyl alcohol) (PVA) to obtain antimicrobial QuB-PVA composite microgels. Furthermore, QuB-PVA microgels were utilized as raw materials to produce xerogel films via an electrospray technique. The as-prepared QuB-PVA xerogel films exhibited excellent bacteriostasis, antioxidation, biocompatibility, self-healing, accelerated skin regeneration and functional restoration, and promoted skin wound healing. The QuB-PVA films significantly facilitated the in vivo healing speed of full-thickness skin wounds compared to commercial dressings. We believe that the present multifunctional QuB-PVA xerogel film is an excellent candidate for the wound dressings.

The innovative fabrication of nano-natural antimicrobial agent@polymeric microgels-TiO2 hybrid films capable of absorbing UV and antibacterial on touch screen panel

It is significant to develop a protective film (coating) for touch screen panels with combined absorbing UV and antibacterial performances. This work developed a smart strategy to fabricate multifunctional protective films for touch screen panels. Polymeric microgels of polyquaternium-10 (PQ) and sodium alginate (SA) were firstly fabricated based on electrostatic interactions. The PQ-SA microgels solution was then cast on a glass substrate to produce PQ-SA films. Further, peroxo titanic acid as cross-linking agent was employed to cross link PQ-SA films via forming coordination bonds between polymers and Ti of peroxo titanic acid, whereafter TiO₂ nanoparticles were generated in situ in PQ-SA films by hydrolyzing the peroxo titanic acid to endow PQ-SA films with excellent absorbing UV ability. Moreover, water-soluble quercetin and resveratrol nanoparticles are fabricated by incorporating solvent exchange method and borate esterification reaction and were loaded into the PQ-TiO₂-SA films to give the films good antibacterial performance. The as-prepared multifunctional films not only exhibited excellent absorbing UV, filtering visible light and antibacterial properties, but also possessed good water resistance, abrasion resistance, self-healing performances and high adhesion to a glass substrate. We believe that present multifunctional film as a protective film for touch screen panels can provide protection for users.

Layer-by-layer films containing emodin or emodin encapsulated in liposomes for transdermal applications

Dermal drug release systems are an important area of research because they can be applied to the skin in a non-invasive procedure using a lower concentration of drugs. In this study, we have developed two types of Layer-by-Layer (LbL) films for releasing emodin (EM). In one system, EM was intercalated with poly(ethylenimine) PEI and poly(vinyl sufonate) (PVS) polyelectrolytes, forming (PEI/PVS)₂(PEI/EM)₇; in another, EM was incorporated in liposomes obtained by mixing dipalmitoyl phosphatidyl glycerol (DPPG) and palmitoyl oleoyl phosphatidyl glycerol (POPG) lipids, forming (PEI/PVS)₂(PEI/DPPG-POPG-EM)₇. UV-vis and FTIR spectroscopies were used to characterize the LbL films. These showed that the depositions of material by LbL were efficient, with increases in the absorbance of each bilayer evidencing the presence of EM in the film. The (PEI/PVS)₂(PEI/EM)₇ and (PEI/PVS)₂(PEI/DPPG-POPG-EM)₇ films released EM in three and five days, respectively. The cyclic voltammetry (CV) assay of the (PEI/PVS)₂(PEI/EM)₇ results are in agreement with UV-vis measurements, which suggest that EM was protonated in acid environments, while the CV of (PEI/PVS)₂(PEI/DPPG-POPG-EM)₇ demonstrated distinct protonation behaviour for EM within the inner liposome structure, even in acid solutions. Therefore, this study presents two systems based on LbL films and provides additional details about the release of EM from these films to create a viable alternative for transdermal applications.