Graphene-Based Materials for Inhibition of Wound Infection and Accelerating Wound Healing

Bacterial infection of the wound could potentially cause serious complications and an enormous medical and financial cost to the rapid emergence of drug-resistant bacteria. Nanomaterials are an emerging technology, that has been researched as possible antimicrobial nanomaterials for the inhibition of wound infection and enhancement of wound healing. Graphene is 2-dimensional (2D) sheet of sp² carbon atoms in a honeycomb structure. It has superior properties, strength, conductivity, antimicrobial, and molecular carrier abilities. Graphene and its derivatives, Graphene oxide (GO) and reduced GO (rGO), have antibacterial activity and could damage bacterial morphology and lead to the leakage of intracellular substances. Besides, for wound infection management, Graphene-platforms could be functionalized by different antibacterial agents such as metal-nanoparticles, natural compounds, and antibiotics. The Graphene structure can absorb near-infrared wavelengths, allowing it to be used as antimicrobial photodynamic therapy. Therefore, Graphene-based material could be used to inhibit pathogens that cause serious skin infections and destroy their biofilm community, which is one of the biggest challenges in treating wound infection. Due to its agglomerated structure, GO hydrogel could entrap and stack the bacteria; thus, it prevents their initial attachment and biofilm formation. The sharp edges of GO could destroy the extracellular polymeric substance surrounding the biofilm and ruin the biofilm biomass structure. As well as, Chitosan and different natural and synthetic polymers such as collagen and polyvinyl alcohol (PVA) also have attracted a great deal of attention for use with GO as wound dressing material. To this end, multi-functional polymers based on Graphene and blends of synthetic and natural polymers can be considered valid non-antibiotic compounds useful against wound infection and improvement of wound healing. Finally, the global wound care market size was valued at USD 20.8 billion in 2022 and is expected to expand at a compound annual growth rate (CAGR) of 5.4% from 2022 to 2027 (USD 27.2 billion). This will encourage academic as well as pharmaceutical and medical device industries to investigate any new materials such as graphene and its derivatives for the treatment of wound healing.

Photo-initiated enhanced antibacterial therapy using a non-covalent functionalized graphene oxide nanoplatform

This study describes a novel antibacterial phototherapeutic platform for highly efficient healing of bacteria-infected wounds. It is based on the photodynamic and physical actions of a zinc tetraaminophthalocyanine-modified graphene oxide nanocomposite produced via non-covalent functionalization. The nanocomposite is positively charged and can easily capture negatively charged bacteria via electrostatic interactions. The antibacterial action is two-fold: (1) reactive oxygen species are produced by the phthalocyanine photosensitizer after short-term exposure to 680 nm light and (2) the graphene oxide can physically cut bacterial cell membranes. These enhanced activities can kill Gram-positive and Gram-negative bacteria at very low dosages. An ultrastructural examination indicates that this nanocomposite causes enormous damage to bacterial morphology and leakage of intracellular substances that lead to bacterial death. A rat wound model is used to demonstrate that the proposed phototherapeutic platform has low cytotoxicity and can promote rapid healing in bacteria-infected wounds. These results suggest that the integration of different antibacterial methods into a single nanotherapeutic platform is a promising strategy for anti-infective treatment.

Covalent Immobilization of Organic Photosensitizers on the Glass Surface: Toward the Formation of the Light-Activated Antimicrobial Nanocoating

Two highly efficient commercial organic photosensitizers—azure A (AA) and 5-(4-aminophenyl)-10,15,20-(triphenyl)porphyrin (APTPP)—were covalently attached to the glass surface to form a photoactive monolayer. The proposed straightforward strategy consists of three steps, i.e., the initial chemical grafting of 3-aminopropyltriethoxysilane (APTES) followed by two chemical postmodification steps. The chemical structure of the resulting mixed monolayer (MIX_TC_APTES@glass) was widely characterized by X-ray photoelectron (XPS) and Raman spectroscopies, while its photoactive properties were investigated in situ by UV–Vis spectroscopy with α-terpinene as a chemical trap. It was shown that both photosensitizers retain their activity toward light-activated generation of reactive oxygen species (ROS) after immobilization on the glassy surface and that the resulting nanolayer shows high stability. Thanks to the complementarity of the spectral properties of AA and APTPP, the effectiveness of the ROS photogeneration under broadband illumination can be optimized. The reported light-activated nanocoating demonstrated promising antimicrobial activity toward Escherichia coli (E. coli), by reducing the number of adhered bacteria compared to the unmodified glass surface.

Turning Photons into Drugs: Phthalocyanine-Based Photosensitizers as Efficient Photoantimicrobials

One of the most promising alternatives for treating bacterial infections is antimicrobial photodynamic therapy (aPDT), making the synthesis and application of new photoactive compounds called photosensitizers (PS) a dynamic research field. In this regard, phthalocyanine (Pc) derivatives offer great opportunities due to their extraordinary light-harvesting and tunable electronic properties, structural versatility, and stability. This Review, rather than focusing on synthetic strategies, intends to overview current progress in the structural design strategies for Pcs that could achieve effective photoinactivation of microorganisms. In addition, the Review provides a concise look into the recent developments and applications of nanocarrier-based Pc delivery systems.

Polymyxin B-functionalized phthalocyanine for chemo-photodynamic antibacterial therapy in enhanced wound healing

The rapid healing of bacteria-infected wounds was achieved via synergistic photodynamic antimicrobial therapy and chemotherapy using polymyxin B-functionalized phthalocyanine.

Photoisomerization and optical properties of a subphthalocyanine–azobenzene–subphthalocyanine triad

A novel subPc–AB–subPc triad exhibits on–off switching of the fluorescence emission intensity upon reversible trans ↔ cis photoisomerization of the azobenzene moiety. NMR spectroscopy provides additional evidence for the conformational change.

Porphyrinated polyimide honeycomb films with high thermal stability for HCl gas sensing

Thermally stable films with ordered pores are fabricated from porphyrinated polyimides and they exhibit excellent property in HCl gas sensing.

Synthesis of core cross-linked star polystyrene with functional end groups and self-assemblies templated by breath figures

We report the synthesis of core cross-linked star (CCS) polymers with functional end groups for self-assembled films, which show mono-layer and multi-layer transition, depending on arm numbers, arm length, and end groups.

Multiple interfaces in self-assembled breath figures

Progress in the breath figure method is reviewed by emphasizing the role of the multiple interfaces and the applications of honeycomb films in separation, biocatalysis, biosensing, templating, stimuli-responsive surfaces and adhesive surfaces.