cRGD peptide incorporated with patchouli alcohol loaded silk fibroin nanoparticles for enhanced targeting of inflammatory sites in colitis

Smart Silk-Based In Situ Sol-Gel Modulates Rectal Microenvironment for Effective Ulcerative Colitis Alleviation

Ulcerative colitis (UC) is a chronic inflammatory bowel disease, with untreated cases often progressing to colorectal cancer. Current treatments aim to induce inflammatory remission but often neglect the surrounding microenvironment, which significantly impairs mucosal healing and contributes to treatment failures. This study presents a novel silk fibroin-based fucoidan (SFU) in situ rectal gel, with sol-gel transition confirmed through rheological analysis under physiological pH and temperature conditions. The SFU gel exhibits strong antioxidant activity, achieving a DPPH radical scavenging rate of 73.3 ± 1.52%. The gel efficiently reduces reactive oxygen species (ROS) and nitric oxide (NO) production, demonstrating its reliable antioxidant effects. In a DSS-induced UC mouse model, SFU effectively alleviates colitis symptoms, including weight loss and disease activity index (DAI) reduction, with improved stool consistency and reduced rectal bleeding. Moreover, SFU therapy reprograms macrophages from proinflammatory M1 to anti-inflammatory M2 phenotypes, significantly lowering IL-6 and TNF-α levels, suggesting anti-inflammatory properties. Furthermore, SFU increased tight junction proteins Occludin-1 and ZO-1, indicating gut mucosal barrier integrity. SFU treatment restores goblet cells and mucin production while preventing fibrosis, demonstrating its potential as a natural therapy for UC treatment.

A bigel co-delivering highly hydrophilic and hydrophobic natural compounds for enhanced ulcerative colitis therapy

Bigel, formed by high-speed shearing of hydrogel and oleogel, is suited to deliver both lipophilic and hydrophilic active compounds. Patchouli oil and paeoniflorin, despite their potential in treating ulcerative colitis, face challenges due to patchouli oil's poor aqueous solubility and paeoniflorin's high solubility but low permeability. In this study, we developed an oral colon-targeted bigel system to co-deliver patchouli oil and paeoniflorin for treating ulcerative colitis. Patchouli oil served as both a therapeutic agent and an oil phase (excipient). The bigel system enhanced mechanical stability, prolonging retention at the colon and enabling effective colon-targeted drug delivery. Compared to oleogel, bigel significantly alleviated symptoms in DSS-induced colitis in mice, reduced inflammatory cytokine release, repaired intestinal mucosal damage, and regulated immune cell populations in the gut. The combination of patchouli oil and paeoniflorin in the bigel exerted a synergistic effect on ulcerative colitis treatment. This work underscores the efficacy of bigel in delivering a combination of hydrophilic and lipophilic drugs, offering a novel strategy for enhanced drug delivery in ulcerative colitis. It also provides a delivery platform technology for volatile oils.

Compliant immune response of silk-based biomaterials broadens application in wound treatment

The unique properties of sericin and silk fibroin (SF) favor their widespread application in biopharmaceuticals, particularly in wound treatment and bone repair. The immune response directly influences wound healing cycle, and the extensive immunomodulatory functions of silk-based nanoparticles and hydrogels have attracted wide attention. However, different silk-processing methods may trigger intense immune system resistance after implantation into the body. In this review, we elaborate on the inflammation and immune responses caused by the implantation of sericin and SF and also explore their anti-inflammatory properties and immune regulatory functions. More importantly, we describe the latest research progress in enhancing the immunotherapeutic and anti-inflammatory effects of composite materials prepared from silk from a mechanistic perspective. This review will provide a useful reference for using the correct processes to exploit silk-based biomaterials in different wound treatments.

Self-Assembled Polymers for Gastrointestinal Tract Targeted Delivery through the Oral Route: An Update

Gastrointestinal tract (GIT) targeted drug delivery systems have gained growing attention as potential carriers for the treatment of different diseases, especially local colonic diseases. They have lower side effects as well as enhanced oral delivery efficiency because of various therapeutics that are vulnerable to acidic and enzymatic degradation in the upper GIT are protected. The novel and unique design of self-assembled nanostructures, such as micelles, hydrogels, and liposomes, which can both respond to external stimuli and be further modified, making them ideal for specific, targeted medical needs and localized drug delivery treatments through the oral route. Therefore, the aim of this review was to summarize and critically discuss the pharmaceutical significance and therapeutic feasibility of a wide range of natural and synthetic biomaterials for efficient drug targeting to GIT using the self-assembly method. Among various types of biomaterials, natural and synthetic polymer-based nanostructures have shown promising targeting potential due to their innate pH responsiveness, sustained and controlled release characteristics, and microbial degradation in the GIT that releases the encapsulated drug moieties.

Progress in silk and silk fiber-inspired polymeric nanomaterials for drug delivery

The fields of drug and gene delivery have been revolutionized by the discovery and characterization of polymer-based materials. Polymeric nanomaterials have emerged as a strategy for targeted delivery because of features such as their impressive biocompatibility and improved availability. Use of naturally derived polymers in these nanomaterials is advantageous due to their biodegradability and bioresorption. Natural biopolymer-based particles composed of silk fibroins and other silk fiber-inspired proteins have been the focus of research in drug delivery systems due to their simple synthesis, tunable characteristics, and ability to respond to stimuli. Several silk and silk-inspired polymers contain a high proportion of reactive side groups, allowing for functionalization and addition of targeting moieties. In this review, we discuss the main classes of silk and silk-inspired polymers that are being used in the creation of nanomaterials. We also focus on the fabrication techniques used in generating a tunable design space of silk-based polymeric nanomaterials and detail how that translates into use for drug delivery to several distinct microenvironments.