Multifunctional Therapeutic Nanodiamond Hydrogels for Infected-Wound Healing and Cancer Therapy.

Wound infection and tumor recurrence are the two main threats to cancer patients after surgery. Although researchers have developed new treatment systems to address the two significant challenges simultaneously, the potential side effects of the heavy-metal-ion-based treatment systems still severely limit their widespread application in therapy. In addition, the wounds from tumor removal compared with general operative wounds are more complex. The tumor wounds mainly exhibit more hemorrhage, larger trauma area, greater vulnerability to bacterial infection, and residual tumor cells. Therefore, a multifunctional treatment platform is urgently needed to integrate rapid hemostasis, sterilization, wound healing promotion, and antitumor functions. In this work, nanodiamonds (NDs), a material that has been well proven to have excellent biocompatibility, are added into a solution of acrylic-grafted chitosan (CEC) and oxidized hyaluronic acid (OHA) to construct a multifunctional treatment platform (CEC-OHA-NDs). The hydrogels exhibit rapid hemostasis, a wound-healing-promoting effect, excellent self-healing, and injectable abilities. Moreover, CEC-OHA-NDs can effectively eliminate bacteria and inhibit tumor proliferation by the warm photothermal effect of NDs under tissue-penetrable near-infrared laser irradiation (NIR) without cytotoxicity. Consequently, we adopt a simple and convenient strategy to construct a multifunctional treatment platform using carbon-based nanomaterials with excellent biocompatibility to promote the healing of infected wounds and to inhibit tumor cell proliferation simultaneously.

Skin-adhesive and self-healing diagnostic wound dressings for diabetic wound healing recording and electrophysiological signal monitoring.

Performing efficient wound management is essential for infected diabetic wounds due to the complex pathology. Flexible electronics have been recognized as one of the promising solutions for wound management. Herein, a kind of skin-adhesive and self-healing flexible bioelectronic was developed, which could be employed as a diagnostic wound dressing to record diabetic wound healing and monitor electrophysiological signals of the patients. The flexible substrate of diagnostic wound dressings showed excellent tissue adhesive (to various substrates including biological samples), self-healing (fracture strength restores by 96%), and intrinsic antibacterial properties (antibacterial ratio >96% against multidrug-resistant bacteria). The diagnostic wound dressings could record the glucose level (1-30 mM), pH values (4-7), and body temperature (18.8-40.0 °C) around the infected diabetic wounds. Besides, the dressings could help optimize treatment strategies based on electrophysiological signals of patients monitored in real-time. This study contributes to developing flexible bioelectronics for the diagnosis and management of diabetic wounds.

CuS-PNIPAm nanoparticles with the ability to initiatively capture bacteria for photothermal treatment of infected skin.

Copper sulfide nanoparticles (CuS NPs) have shown great potential in various application fields, especially in biomedical engineering fields. CuS NPs, with the ability to actively capture and kill bacteria and without the worry of biocompatibility, will greatly expand their applications. Herein, a four-arm star thermo-sensitive polyisopropylacrylamide (4sPNIPAm) was used to modify CuS NPs (CuS-PNIPAm NPs). The obtained NPs displayed the controlled release of copper ions and higher photothermal conversion ability in comparison with contrast materials CuS-PEG NPs and CuS NPs. Aggregation of CuS-PNIPAm NPs at above 34°C resulted in capturing bacteria by forming the aggregates of NPs-bacteria. Both Staphylococcus aureus and Escherichia coli co-cultured with CuS-PNIPAm NPs were completely killed upon near-infrared irradiation in minutes. Furthermore, CuS-PNIPAm NPs were verified to be a photothermal agent without toxic effect. In in vivo experiment, the NPs effectively killed the bacteria in the wound and accelerated the process of wound repairment. Overall, photothermal treatment by CuS-PNIPAm NPs demonstrates the ability to actively capture and kill bacteria, and has a potential in the treatment of infected skin and the regeneration of skin tissues. The therapy will exert a far-reaching impact on the regeneration of stubborn chronic wounds.

Injectable Self-Healing Hydrogels Containing CuS Nanoparticles with Abilities of Hemostasis, Antibacterial activity, and Promoting Wound Healing.

Injectable self-healing hydrogels containing functional nanoparticles (NPs) have attracted much attention in many fields of biomedicine. A series of injectable self-healing hydrogels containing PEGylation CuS NPs based on N-carboxyethyl chitosan (CEC) and oxidized sodium alginate (OA) were developed by taking advantages of the unique functions of CuS NPs and chitosan, referred to as CuS NP hydrogels or CEC-OAm-CuSn, where "m" stands for the concentration percentage of the added OA solution (w/v) and "n" represents the molar concentration of CuS NPs in the hydrogels. The physical properties of CuS NP hydrogels, syringeability, rapid self-repair ability, and photothermal performance were systematically investigated. The multiple functions for CuS NP hydrogels requested in the skin healing process were explored. The results showed that CuS NP hydrogels had not only adjustable physical properties and good injectable self-healing characteristics but also excellent functionalities, concurrently including hemostatic ability, bacteria killing capability, and cell migration and proliferation promotion. In vivo wound healing and histomorphological examinations of immunofluorescence staining in a mouse full-thickness wound model demonstrated good acceleration effects of these hydrogels for infected wound healing. Therefore, these injectable self-healing CuS NP hydrogels which possess the abilities of hemostasis, antibacterial activity, and infected-wound healing promotion exhibit great potential as in situ wound dressings.