Bletilla striata Polysaccharide-/Chitosan-Based Self-Healing Hydrogel with Enhanced Photothermal Effect for Rapid Healing of Diabetic Infected Wounds via the Regulation of Microenvironment

The management of diabetic ulcers poses a significant challenge worldwide, and persistent hyperglycemia makes patients susceptible to bacterial infections. Unfortunately, the overuse of antibiotics may lead to drug resistance and prolonged infections, contributing to chronic inflammation and hindering the healing process. To address these issues, a photothermal therapy technique was incorporated in the preparation of wound dressings. This innovative solution involved the formulation of a self-healing and injectable hydrogel matrix based on the Schiff base structure formed between the oxidized Bletilla striata polysaccharide (BSP) and hydroxypropyltrimethylammonium chloride chitosan. Furthermore, the introduction of CuO nanoparticles encapsulated in polydopamine imparted excellent photothermal properties to the hydrogel, which promoted the release of berberine (BER) loaded on the nanoparticles and boosted the antibacterial performance. In addition to providing a reliable physical protection to the wound, the developed hydrogel, which integrated the herbal components of BSP and BER, effectively accelerated wound closure via microenvironment regulation, including alleviated inflammatory reaction, stimulated re-epithelialization, and reduced oxidative stress based on the promising results from cell and animal experiments. These impressive outcomes highlighted their clinical potential in safeguarding the wound against bacterial intrusion and managing diabetic ulcers

The overall distribution of the pathogens from July 2009 to June 2014.

<p>A, the positive detection rates (PDRs) according to patient total, sex, age and its subgroups; B, the PDRs of 5 different disease subgroups. (1) SAURTIG: The single acute upper RTI group. (2) SALRTIG: The single acute lower RTI group. (3) RTICLDG: The RTI with chronic lung disease group. (4) RTISNPSG: The RTI with severe non-pulmonary symptoms group. (5) RTIIDG: The RTI with immunocompromised diseases group; C, yearly PDRs; D, seasonal PDRs.</p

Pathogens’ distributions within age subgroups over five years.

<p>A, PDR differences in pediatric and adults subgroups; the (%) in B, B-1, C, D, and E indicates the PDRs of pathogens in different age subgroups.</p

The distribution of co-infections over five years.

<p>A, CIRs for different pathogens; B, the 4 highest pathogen CIRs and their constituent ratios.</p

Pathogens’ prevalence over 5 years.

<p>A, the total number of samples and the PDR patterns in each month of each year; B, the prevalence patterns of different pathogens over five years; <b>C</b>, prevalence peaks over 5 years: one peak (lines in blue), two peaks (lines in red), and three peaks (lines in orange), (%):typical indicates the positive rate of pathogens; D, the yearly prevalence patterns of the 4 types of HCoV and 4 types of PIV.</p

The prevalence of different respiratory pathogens from July 2009 to June 2014.

<p>No. (<b>%</b>) of each group except where specifically stated.</p><p><b><i>P</i></b>^{<b><i>$</i></b>}: Represents the P values comparing male and female groups.</p><p><b><i>P</i></b>*: Represents the P values comparing the five disease groups: (1) SAURTIG: The single acute upper RTI group. (2) SALRTIG: The single acute lower RTI group. (3) RTICLDG: The RTI with chronic lung disease group. (4) RTISNPSG: The RTI with severe non-pulmonary symptoms group. (5) RTIIDG: The RTI with immunocompromised disease group.</p><p>^#: The pathogen with the highest PDR.</p><p>The prevalence of different respiratory pathogens from July 2009 to June 2014.</p