Fabrication and characterization of thin self-rolling film for anti-inflammatory drug delivery

Thin films have been identified as an alternative approach for targeting sensitive site as drug delivery tool. In this work, the preparation of self-rolling thin films to form tubes for wound healing and easy placement (e.g. in the colon via colonoscopy) have been studied. We explored the use of thin films as a protective dressing combined to local release of an anti-inflammatory in order to improve drug efficacy and limit the side effects of the oral route. Non-cytotoxic poly(ethylene) glycol and poly(lactic acid) photo-crosslinkable star copolymers were used for rapid UV crosslinking of bilayered films loaded with prednisolone. The films, crosslinked under UV lamp without the need of photoinitiator, are optimized and compared in terms of water uptake, swelling ratio, final tube diameter and morphology, anti-inflammatory drug loading and release. Our studies showed the spontaneous rolling of bilayer constructs directly after immersion in water. Tubular geometry allows application of the patch through minimally invasive procedures such as colonoscopy. Moreover, the rolled-up bilayers highlighted efficient release of encapsulated drug following Fickian diffusion mechanism. We also confirmed the anti-inflammatory activity of the released anti-inflammatory drug that inhibits the pro-inflammatory cytokine IL-1β in RAW 264.7 macrophages stimulated by Escherichia coli (E. coli).

pH factors in chronic wound and pH-responsive polysaccharide-based hydrogel dressings

Chronic wounds present a significant healthcare challenge marked by complexities such as persistent bleeding, inhibited cell proliferation, dysregulated inflammation, vulnerability to infection, and compromised tissue remodeling. Conventional wound dressings often prove inadequate in addressing the intricate requirements of chronic wound healing, leading to slow healing and heightened susceptibility to infections in patients with prolonged medical conditions. Bacterial biofilms in chronic wounds pose an additional challenge due to drug resistance. Advanced wound dressings have emerged as promising tools in expediting the healing process. Among these, pH-responsive polysaccharide-based hydrogels exhibit immense prospect by adapting their functions to dynamic wound conditions. Despite their potential, the current literature lacks a thorough review of these wound dressings. This review bridges this gap by meticulously examining factors related to chronic wounds, current strategies for healing, and the mechanisms and potential applications of pH-responsive hydrogel wound dressings as an emerging therapeutic solution. Special focus is given to their remarkable antibacterial properties and significant self-healing abilities. It further explores the pH-monitoring functions of these dressings, elucidating the associated pH indicators. This synthesis of knowledge aims to guide future research and development in the field of pH-responsive wound dressings, providing valuable insights into their potential applications in wound care.

Evaluation of Opuntia-carrageenan superporous hydrogel (OPM-CRG SPH) as an effective biomaterial for drug release and tissue scaffold

The process of wound healing involves complex interplay of systems biology, dependent on coordination of various cell types, both intra and extracellular mechanisms, proteins, and signaling pathways. To enhance these interactions, drugs must be administered precisely and continuously, effectively regulating the intricate mechanisms involved in the body's response to injury. Controlled drug delivery systems (DDS) play a pivotal role in achieving this objective. A proficient DDS shields the wound from mechanical, oxidative, and enzymatic stress, against bacterial contamination ensuring an adequate oxygen supply while optimizing the localized and sustained delivery of drugs to target tissue. A pH-sensitive SPH was designed by blending two natural polysaccharides, Opuntia mucilage and carrageenan, using microwave irradiation and optimized according to swelling index at pH 1.2, 7.0, and 8.0 and % porosity. Optimized grade was analyzed for surface hydrophilicity-hydrophobicity using OCA. Analytical characterizations were performed using FTIR, TGA, XRD, DSC, reflecting semicrystalline behavior. Mechanical property confirmed adequate strength. In vitro drug release study with ciprofloxacin-HCL as model drug showed 97.8 % release within 10 h, fitting to the Korsmeyer-Peppas model following diffusion and erosion mechanism. In vitro antimicrobial, anti-inflammatory assays, zebrafish toxicity, and animal studies in mice with SPH concluded it as a novel biomaterial.

A new perspective on quantitative assessment of photodynamic therapy mediated hydrogel nanocomposite in wound healing using objective biospeckle and morphological local-gradient

Skin wounding is a serious public health issue, especially when considering factors that accelerate tissue recovery. Consequently, the use of photodynamic therapy (PDT) as an effective wound-healing treatment has attracted more scientific attention. Although assessing the wound healing rate is crucial for appropriate monitoring of the probability of wound healing and evaluating the treatment efficiency, the currently used techniques lack the ability to provide such information. Therefore, this study has two aims, first, it contributes to the development of a new image-guided biospeckle system for quantitative monitoring of skin wound healing rate. Second, it evaluates the potential of using a novel synthesized PDT-mediated polyethylene glycol fabric with methylene blue (PEG-MB) hydrogel nanocomposite in accelerating wound healing. The proposed imaging system initially acquires raw biospeckle images from the wound regions of adult healthy albino mice treated with the synthesized hydrogel nanocomposite. Each raw biospeckle image is then converted into maps of morphological local-gradient matrices implemented from the combination of dilation and erosion operations at different radii up to 25 pixels. Subsequently, their intensity histogram statistics are computed, taking central moments as the feature set. Final characterization is achieved via a linear combination of the biospeckle statistics maintaining as much variance as possible using principal component analysis (PCA). The results confirmed by cytokine concentration measurement and histological investigation demonstrate that the innovative biospeckle image-guided system is ideal for investigating wound healing and suggest the potential of the hydrogel nanocomposite as an active dressing.

Fabrication of 3D Gelatin Hydrogel Nanocomposite Impregnated Co-Doped SnO2 Nanomaterial for the Catalytic Reduction of Environmental Pollutants

In the catalytic reduction of various environment pollutants, cobalt-doped tin oxide, i.e., Co-SnO₂ intercalated gelatin (GL) hydrogel nanocomposite was prepared via direct mixing of Co-SnO₂ doped with GL. Then, it was crosslinked internally using formaldehyde within a viscous solution of gelatin polymer, which led to the formation of GL/Co-SnO₂ hydrogel nanocomposite. GL/Co-SnO₂ hydrogel nanocomposite was fully characterized by using field-emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDX), powder X-ray diffraction (XRD), and attenuated total reflection–Fourier transform infrared spectroscopy (ATR-FTIR). The FESEM images indicate that the Co-SnO₂ composite has a spherical structure on the GL matrix while EDX elucidates the elemental composition of each atom in the crosslinked GL/Co-SnO₂ hydrogel nanocomposite. The GL/Co-SnO₂ nanocomposite was checked for the reduction of various pollutants, including 2-nitro-phenol (2-NP), 2,6-dinitro-phenol (2,6-DNP), 4-nitro-phenol (4-NP), Congo red (CR), and methyl orange (MO) dyes with a strong sodium borohydride (NaBH₄) reducing agent. The GL/Co-SnO₂ nanocomposite synergistically reduced the MO in the presence of the reducing agent with greater reduction rate of 1.036 min⁻¹ compared to other dyes. The reduction condition was optimized by changing various parameters, such as the catalyst amount, dye concentration, and the NaBH₄ amount. Moreover, the GL/Co-SnO₂ nanocomposite catalyst can be easily recovered, is recyclable, and revealed minimal loss of nanomaterials.

Recent Advances in ROS-Sensitive Nano-Formulations for Atherosclerosis Applications

Over the past decade, ROS-sensitive formulations have been widely used in atherosclerosis applications such as ROS scavenging, drug delivery, gene delivery, and imaging. The intensified interest in ROS-sensitive formulations is attributed to their unique self-adaptive properties, involving the main molecular mechanisms of solubility switch and degradation under the pathological ROS differences in atherosclerosis. This review outlines the advances in the use of ROS-sensitive formulations in atherosclerosis applications during the past decade, especially highlighting the general design requirements in relation to biomedical functional performance.

Synergistic therapy of magnetism-responsive hydrogel for soft tissue injuries

Soft tissue injury is very common and associated with pain, tissue swelling and even malformation if not treated on time. Treating methods include cryotherapy, electrical therapy, ultrasound therapy and anti-inflammatory drug, but none of them is completely satisfying. In this work, for a better therapeutic effect, drug therapy and pulsed electromagnetic field (PEMF) therapy were combined. We constructed a drug delivery system using the tetra-PEG/agar hydrogel (PA). By incorporating Fe3O4 NPs into the hydrogel network, a magnetism-responsive property was achieved in the system. The cytotoxicity and in vivo study showed a good biocompatibility of the PA/Fe3O4 hydrogel. A magnetism-controlled release was attained by the incorporation of Fe3O4. Finally, in vivo study showed a better performance of the DS-loaded PA/Fe3O4 compared with the commercially available DS ointment regarding the recovery of the injured soft tissue. Therefore, this magnetism-responsive hydrogel may represent a promising alternative to treat soft tissue injury.