Improving curcumin bactericidal potential against multi-drug resistant bacteria via its loading in polydopamine coated zinc-based metal-organic frameworks

A chitosan-modified tea tree oil self-nanoemulsion improves antibacterial effects in vivo and in vitro and promotes wound healing by influencing metabolic processes against multidrug-resistant bacterial infections

Infectious diseases, especially multidrug-resistant bacterial infections, have caused crises and majorly disrupted public health and economic stability worldwide. Many natural essential oils, especially tea tree oil, have potential to treat multidrug-resistant bacteria, such as H. pylori and P. aeruginosa. However, there are some problems need to be solved, such as poor stability upon light or oxygen exposure. Therefore, it is urgent to develop the ideal formation to tackle these difficulties. Herein, we reported the novel chitosan-modified self-nanoemulsion (TNE) encapsulating natural essential tea tree oil with strong antibacterial and stability characterize. In this study, we found that this self-nanoemulsion (size: 212 nm, PDI: 0.124, zeta potential: -20.5 mV, 6 % tea tree oil) not only had physical properties, good stability and tissue safety, but also had better antibacterial synergism (2-8 times) than that of water suspension against various multidrug-resistant bacterial (such as H. pylori, MRSA and P. aeruginosa). Additionally, TNE showed high antibacterial effectiveness in vivo, reduced inflammation, promoted ulcer healing after H. pylori infection and accelerated wound healing after P. aeruginosa infection. Importantly, this novel self-nanoemulsion can induce 274 protein down-regulated and 251 protein up-regulated, and disrupt H. pylori metabolic processes (glyoxylate, dicarboxylic acid, glutamate and tryptophan metabolism) and reduced its viability, leading to significant synergistic antibacterial effects. TNE is a potential treatment for skin wounds or ulcers caused by multidrug-resistant bacterial infections.

Design and Development of a Self-nanoemulsifying Drug Delivery System for Co-delivery of Curcumin and Naringin for Improved Wound Healing Activity in an Animal Model

The present study endeavored to design and develop a self-nanoemulsifying drug delivery system to improve the solubility and dermatological absorption of curcumin and naringin. Curcumin and naringin-loaded self-nanoemulsifying drug delivery system formulations were developed using aqueous phase titration. Phase diagrams were used to pinpoint the self-nanoemulsifying drug delivery system zones. Tween 80 and Labrasol (surfactants), Transcutol (cosurfactant), and cinnamon oil were chosen from a large pool of surfactants, cosurfactants, and oils based on their solubility and greatest nano-emulsion region. Fourier transform infrared spectroscopy, zeta sizer, and atomic force microscopy were used to characterize the optimized formulations and test for dilution and thermodynamic stability. The optimized curcumin-naringin-self-nanoemulsifying drug delivery system demonstrated the following characteristics: polydispersity index (0.412 ± 0.03), % transmittance (97%), particle size (212.5 ± 05 nm), zeta potential (- 25.7 ± 1.80 mV) and having a smooth and spherical droplet shape, as shown by atomic force microscopy. The ability of their combined formulation to cure wounds was tested in comparison to pure curcumin suspension, empty self-nanoemulsifying drug delivery system, and standard fusidic acid. Upon topical administration, the optimized curcumin-naringin-self-nanoemulsifying drug delivery system demonstrated significant wound healing activity in comparison with a pure curcumin suspension, empty self-nanoemulsifying drug delivery system, and standard fusidic acid. Based upon this result, we assume that skin penetration was increased by using the optimized curcumin-naringin-self-nanoemulsifying drug delivery system with enhanced solubility.

Chemo-photothermal therapy of bacterial infections using metal-organic framework-integrated polymeric network coatings

Surface modification of biomedical materials and devices using versatile nanocomposite coatings holds great promise for improving functionalities to defend against life-threatening bacterial infections. In this study, a one-step surface modification strategy was developed to deposit gold nanorods (AuNRs)- and curcumin (CUR)-encapsulated zeolitic imidazolate framework-8 (ZIF-8) nanoparticles (AuNRs-ZIF-CUR NPs or AZC) onto phytic acid (PA)-ε-polylysine (Ply) network coatings. In the solution mixture of PA, Ply and AZC, PA interacted with Ply via electrostatic interactions, and can also bind to AZC via metal chelation. The as-formed AZC-PA-Ply aggregates could be deposited onto various substrates via surface adhesion of PA and gravitational effects. The physicochemical and antibacterial properties of the AZC-PA-Ply network coatings on polydimethylsiloxane (PDMS) substrates were evaluated. The sustained release of zinc ions and CUR, as well as the contact-killing ability of Ply, endowed the AZC-PA-Ply network coatings with good antibacterial chemotherapeutic effects. In addition, the embedded AuNRs in the AZC-PA-Ply network coatings exhibited excellent photothermal conversion efficiency for the ablation of bacteria. Upon near-infrared (NIR) laser irradiation, the AZC-PA-Ply-coated PDMS surfaces exhibited strong antibacterial effects by disrupting the membrane integrity and cellular functions of the adhered bacteria. Thus, the AZC-PA-Ply network coatings displayed combined antibacterial chemotherapeutic and photothermal therapeutic effects. Furthermore, the AZC-PA-Ply-coated PDMS substrates exhibited effective bacterial infection prevention and good biocompatibility in an in vivo implant model. Hence, the versatile AZC-PA-Ply network coatings are potentially useful as a multi-modal antibacterial platform to eliminate infectious bacterial pathogens in biomedical applications.

Mechanism of Self-Oxidative Copolymerization and its Application with Polydopamine-pyrrole Nano-copolymers

Currently, the copolymer of dopamine (DA) and pyrrole (PY) via chemical and electrochemical oxidation usually requires additional oxidants, and lacks flexibility in regulating the size and morphology, thereby limiting the broad applications of DA-PY copolymer in biomedicine. Herein, the semiquinone radicals produced by the self-oxidation of DA is ingeniously utilized as the oxidant to initiate the following copolymerization with PY, and a series of quinone-rich polydopamine-pyrrole copolymers (PDAm-nPY) with significantly enhanced absorption in near-infrared (NIR) region without any additional oxidant assistance is obtained. Moreover, the morphology and size of PDAm-nPY can be regulated by changing the concentration of DA and PY, thereby optimizing nanoscale PDA0.05-0.15PY particles (≈ 150 nm) with excellent NIR absorption and surface modification activity are successfully synthesized. Such PDA0.05-0.15PY particles show effective photoacoustic (PA) imaging and photothermal therapy (PTT) against 4T1 tumors in vivo. Furthermore, other catechol derivatives can also copolymerize with PY under the same conditions. This work by fully utilizing the semiquinone radical active intermediates produced through the self-oxidation of DA reduces the dependence on external oxidants in the synthesis of composite materials and predigests the preparation procedure, which provides a novel, simple, and green strategy for the synthesis of other newly catechol-based functional copolymers.

Multi-modal triggered-release sonodynamic/chemo/phototherapy synergistic nanocarriers for the treatment of colon cancer

Most colon cancer patients are diagnosed at an advanced stage, with a grim prognosis. In clinical, various combination therapies have been employed to enhance the efficacy of colon cancer treatment. The essence of combined treatment is the judicious selection and combination of various treatment units. Phototherapy (PT), sonodynamic therapy (SDT), and chemotherapy are treatment modalities that rely on the active molecules to treat tumors, and have been demonstrated to synergistically enhance tumor treatment efficacy. However, the differences in the metabolism of active molecules and hypoxic microenvironment of tumors have limited the synergistic effects of the aforementioned methods. To address this significant issue, in this study, we utilized polydopamine (PDA) as the encapsulated material to form a rigid shell that contains the therapeutic molecules IR-780 and methotrexate (MTX) on the surface of perfluorohexane (PFH) microdroplets through self-assembling method to develop an SDT/chemotherapy/PT combined nanoparticles (SCP NPs). Transmission electron microscopy (TEM) revealed that the nanoparticles exhibited a hollow shell structure, with an average size of approximately 100 nm. SCP NPs have excellent stability and biocompatibility in both in vitro and in vivo. The absorption and emission spectrum of the loaded IR-780 did not exhibit any significant shift, and the photothermal temperature rose to 92°C. Their ultrasonic cavitation effect was good and their cell inhibitory effect of MTX was maintained. SCP NPs can achieve multi-modal triggered release through ultrasound, laser irradiation, and pH, ensuring a simultaneous accumulation of therapeutic molecules in the tumor area and effectively alleviating tumor hypoxia. Additionally, both the near-infrared fluorescence (NIF) signal and the ultrasonic cavitation signal of the nanoparticles can be utilized for tracking and monitoring treatment efficacy. Most notably, SCP NPs exhibited outstanding synergistic treatment effects at low intervention levels, resulting in a 67% cure rate of tumors. These results provide an experimental basis for developing the new clinical treatments for colon cancer.

Effect of curcumin nanoparticles on proliferation and migration of mouse airway smooth muscle cells and airway inflammatory infiltration

Curcumin (CUR) possesses the capability to inhibit various inflammatory factors, exert anti-inflammatory effects, and alleviate asthma attacks; however, its hydrophobicity and instability significantly impede its clinical application. In this study, we synthesized CUR-loaded nanoparticles (CUR-NPs) and evaluated their impact on the proliferation, migration, and inflammatory infiltration of mouse airway smooth muscle cells (ASMCs), while investigating their underlying mechanisms. To achieve this objective, ASMCs were isolated from BALB/c mice and subjected to TGF-β1-induced cell proliferation and migration. Our findings demonstrate that CUR-NPs effectively regulate the release of CUR within cells with superior intracellular uptake compared to free CUR. The CCK-8 assay results indicate that the blank carrier does not exhibit any cytotoxic effects on cells, thus rendering the impact of the carrier itself negligible. The TGF-β1 group exhibited a significant increase in cell proliferation, whereas treatment with CUR-NPs significantly suppressed TGF-β1-induced cell proliferation. The findings from both the cell scratch assay and transwell assay demonstrated that TGF-β1 substantially enhanced cell migration, while CUR-NPs treatment effectively attenuated TGF-β1-induced cell migration. The Western blot analysis demonstrated a substantial increase in the expression levels of TGF-β1, p-STAT3, and CTGF in ASMCs following treatment with TGF-β1 when compared to the control group. Nevertheless, this effect was effectively counteracted upon administration of CUR-NPs. Furthermore, an asthma mouse model was successfully established and CUR-NPs were administered through tail vein injection. The serum levels of TGF-β1 and the expression levels of TGF-β1, p-STAT3, and CTGF proteins in the lung tissue of mice in the model group exhibited significant increases compared to those in the control group. However, CUR-NPs treatment effectively attenuated this change. Our research findings suggest that CUR-NPs possess inhibitory effects on ASMC proliferation, migration, and inflammatory infiltration by suppressing activation of the TGF-β1/p-STAT3/CTGF signaling pathway, thereby facilitating inhibition of airway remodeling.

Nanosphere-reinforced polysaccharide self-healing hydrogels for infected wound healing

Bacterial infection remarkably impedes wound healing, with antibiotics traditionally serving as the primary therapeutic intervention. However, the escalating misuse of antibiotics and the emergence of bacterial resistance present substantial treatment challenges for infected wounds. Consequently, the development of antibiotic-free antimicrobial dressings holds pertinent research and clinical relevance. To this end, this study aimed to introduce an all-natural hydrogel dressing, amalgamating polyphenols and polysaccharides, exhibiting pronounced antibacterial and antioxidant properties without relying on antibiotics. First, we constructed curcumin-tannic acid‑zinc ion nanospheres (CTZN) through self-assembly. Our experimental results showed that the nanospheres had excellent biocompatibility, antioxidant, and antimicrobial abilities. Subsequently, we prepared carboxymethylated chitosan/oxidized sodium alginate hydrogels via Schiff base reactions. Incorporation of CTZN into the hydrogel system not only improves the inherent qualities of the hydrogel but also confers multifunctional properties, including antimicrobial, antioxidant, and anti-inflammatory abilities. In this study, we enhanced the physicochemical properties and biological activity of hydrogels by introducing natural material nanospheres, offering a novel approach that could pave the way for the development of purely natural biomaterial dressings.

Sources, morphology, phytochemistry, pharmacology of Curcumae Longae Rhizoma, Curcumae Radix, and Curcumae Rhizoma: a review of the literature

Curcumae Longae Rhizoma (turmeric), Curcumae Radix and Curcumae Rhizoma are derived from the Curcuma species, and have gradually become three of the most commonly used medicinal herbs in China due to their different origins, processing methods and medicinal part. These three herbs have certain similarities in morphology, chemical composition, and pharmacological effects. All three of these herbs contain curcuminoids and volatile oil compounds, which exhibit anti-inflammatory, anti-tumor, antioxidant, and neuroprotective properties, although modern clinical applications have their own requirements. At present, there is no systematic guidelines for the clinical application of these three of Curcuma species; consequently, there is a high risk of unwanted phenomena associated with the mixing and indiscriminate use of these herbs. In this review, we focus predominantly on morphology, chemical composition, and the pharmacological activity of these three Curcuma herbs and summarize the current status of research in this field. Our goal is to provide a better understanding of clinical value of these Curcuma species so that we can provide reference guidelines for their further development, utilization and rational clinical application.

Flexible Curcumin-Loaded Zn-MOF Hydrogel for Long-Term Drug Release and Antibacterial Activities

Management of chronic inflammation and wounds has always been a key issue in the pharmaceutical and healthcare sectors. Curcumin (CCM) is an active ingredient extracted from turmeric rhizomes with antioxidant, anti-inflammatory, and antibacterial activities, thus showing significant effectiveness toward wound healing. However, its shortcomings, such as poor water solubility, poor chemical stability, and fast metabolic rate, limit its bioavailability and long-term use. In this context, hydrogels appear to be a versatile matrix for carrying and stabilizing drugs due to their biomimetic structure, soft porous microarchitecture, and favorable biomechanical properties. The drug loading/releasing efficiencies can also be controlled via using highly crystalline and porous metal-organic frameworks (MOFs). Herein, a flexible hydrogel composed of a sodium alginate (SA) matrix and CCM-loaded MOFs was constructed for long-term drug release and antibacterial activity. The morphology and physicochemical properties of composite hydrogels were analyzed by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), ultraviolet-visible spectroscopy (UV-Vis), Raman spectroscopy, and mechanical property tests. The results showed that the composite hydrogel was highly twistable and bendable to comply with human skin mechanically. The as-prepared hydrogel could capture efficient CCM for slow drug release and effectively kill bacteria. Therefore, such composite hydrogel is expected to provide a new management system for chronic wound dressings.