Direct Delivery of Apatite Nanoparticle-Encapsulated siRNA Targeting TIMP-1 for Intractable Abnormal Scars

Bioactive Patch for Rotator Cuff Repairing via Enhancing Tendon-to-Bone Healing: A Large Animal Study and Short-Term Outcome of a Clinical Trial

Tissue engineering has demonstrated its efficacy in promoting tissue regeneration, and extensive research has explored its application in rotator cuff (RC) tears. However, there remains a paucity of research translating from bench to clinic. A key challenge in RC repair is the healing of tendon-bone interface (TBI), for which bioactive materials suitable for interface repair are still lacking. The umbilical cord (UC), which serves as a vital repository of bioactive components in nature, is emerging as an important source of tissue engineering materials. A minimally manipulated approach is used to fabricate UC scaffolds that retain a wealth of bioactive components and cytokines. The scaffold demonstrates the ability to modulate the TBI healing microenvironment by facilitating cell proliferation, migration, suppressing inflammation, and inducing chondrogenic differentiation. This foundation sets the stage for in vivo validation and clinical translation. Following implantation of UC scaffolds in the canine model, comprehensive assessments, including MRI and histological analysis confirm their efficacy in inducing TBI reconstruction. Encouraging short-term clinical results further suggest the ability of UC scaffolds to effectively enhance RC repair. This investigation explores the mechanisms underlying the promotion of TBI repair by UC scaffolds, providing key insights for clinical application and translational research.

Clinical Study of Rh-bFGF Combined With Collagen Sponge in the Treatment of Maxillofacial Deep Ⅱ Degree Burn

OBJECTIVES

To observe the clinical effect of recombinant human alkaline fibroblast growth factor (rh-bFGF) combined with collagen sponge in the treatment of maxillofacial deepⅡ degree burn.

METHODS

From January 2019 to January 2022, 96 patients with maxillofacial deep Ⅱ degree burns were randomly divided into a control group (N=48) and an observation group (N=48). The observation group was treated with rh-bFGF and collagen sponge after debridement, whereas the control group was treated with silver sulfadiazine ointment after debridement. The healing rate and healing time of the wounds were observed, interleukin (IL)-6, tumor necrosis factor (TNF)-α, IL-10, epidermal growth factor (EGF), endothelial growth factor growth factor (VEGF), and metalloproteinase tissue inhibitor 1 (TIMP-1) were measured. Vancouver Scar Scale (VSS) was used to evaluate the local scar at 6 months after wound healing in both groups.

RESULTS

On the 10th, 14th, and 21st day of treatment, the wound healing rate in the observation group was higher than that in the control group (P<0.05), the wound healing time in the observation group was lower than that in the control group (P<0.05), and on the 14th day of treatment, the levels of TNF-α and IL-6 in the observation group were lower than those in the control group (P<0.05). The levels of IL-10 in the observation group were higher than those in the control group (P<0.05). The levels of EGF, VEGF, and TIMP-1 in the observation group were higher than those in the control group (P<0.05), and the scores of VSS in the observation group were lower than those in the control group (P<0.05).

CONCLUSIONS

Rh-bFGF combined with collagen sponge can decrease the levels of TNF-α and IL-6 and increase the levels of IL-10, which can control the inflammation effectively, at the same time, it can increase the level of EGF, VEGF, and TIMP-1, promote wound healing, and reduce scar hyperplasia. The treatment protocol is simple, safe, effective, and suitable for clinical application.

Hydrogel Loaded with Components for Therapeutic Applications in Hypertrophic Scars and Keloids

Hypertrophic scars and keloids are common fibroproliferative diseases following injury. Patients with pathologic scars suffer from impaired quality of life and psychological health due to appearance disfiguration, itch, pain, and movement disorders. Recently, the advancement of hydrogels in biomedical fields has brought a variety of novel materials, methods and therapeutic targets for treating hypertrophic scars and keloids, which exhibit broad prospects. This review has summarized current research on hydrogels and loaded components used in preventing and treating hypertrophic scars and keloids. These hydrogels attenuate keloid and hypertrophic scar formation and progression by loading organic chemicals, drugs, or bioactive molecules (such as growth factors, genes, proteins/peptides, and stem cells/exosomes). Among them, smart hydrogels (a very promising method for loading many types of bioactive components) are currently favoured by researchers. In addition, combining hydrogels and current therapy (such as laser or radiation therapy, etc.) could improve the treatment of hypertrophic scars and keloids. Then, the difficulties and limitations of the current research and possible suggestions for improvement are listed. Moreover, we also propose novel strategies for facilitating the construction of target multifunctional hydrogels in the future.

Fibrosis in burns: an overview of mechanisms and therapies

Scar development remains a common occurrence and a major healthcare challenge affecting the lives of millions of patients annually. Severe injuries to the skin, such as burns can lead to pathological wound healing patterns, often characterized by dermal fibrosis or excessive scarring, and chronic inflammation. The two most common forms of fibrotic diseases following burn trauma are hypertrophic scars (HSCs) and keloids, which severely impact the patient's quality of life. Although the cellular and molecular mechanisms are similar, HSC and keloids have several distinct differences. In this review, we discuss the different forms of fibrosis that occur postburn injury, emphasizing how the extent of burn influences scar development. Moreover, we highlight how a systemic response induced by a burn injury drives wound fibrosis, including both the role of the inflammatory response, as well as the fate of fibroblast during skin healing. Finally, we list potential therapeutics aimed at alleviating pathological scar formation. An understanding of the mechanisms of postburn fibrosis will allow us to effectively move studies from bench to bedside.

Non-coding RNAs are key players and promising therapeutic targets in atherosclerosis

Cardiovascular disease (CVD) is the primary cause of death in humans. Atherosclerosis (AS) is the most common CVD and a major cause of many CVD-related fatalities. AS has numerous risk factors and complex pathogenesis, and while it has long been a research focus, most mechanisms underlying its progression remain unknown. Noncoding RNAs (ncRNAs) represent an important focus in epigenetics studies and are critical biological regulators that form a complex network of gene regulation. Abnormal ncRNA expression disrupts the normal function of tissues or cells, leading to disease development. A large body of evidence suggests that ncRNAs are involved in all stages of atherosclerosis, from initiation to progression, and that some are significantly differentially expressed during AS development, suggesting that they may be powerful markers for screening AS or potential treatment targets. Here, we review the role of ncRNAs in AS development and recent developments in the use of ncRNAs for AS-targeted therapy, providing evidence for ncRNAs as diagnostic markers and therapeutic targets.

The EGF Motif With CXDXXXXYXCXC Sequence Suppresses Fibrosis in a Mouse Skin Wound Model

BACKGROUND/AIM

Fibrosis is an essential process for wound healing, but excessive fibrosis, such as keloids and hypertrophic scars, can cause cosmetic and functional problems. These lesions are caused by abnormal deposition and shrinkage of collagen fibers. The light chain of FIX, a plasma protein essential for hemostasis, has the amino acid sequence CXDXXXXYXCXC in the EGF domain. Peptides containing this sequence inhibited stromal growth in a mouse transplant tumor model. In this study, the effect of the FIX light chain on wound healing was studied.

MATERIALS AND METHODS

A full-layer wound was made on the back of each mouse, and cDNA encoding the light chain of mouse FIX (F9-LC) in an expression vector was injected locally once each week using a non-viral vector. Histochemical analysis of the wound was then performed to assess the effects on wound healing. Moreover, the effect of F9-LC on fibroblasts was studied in vitro.

RESULTS

Macroscopic observation showed that wounds with forced expression of F9-LC appeared flatter and had fewer wrinkles than control wounds. Tissue collagen staining and immunostaining revealed that administration of F9-LC suppressed collagen 1 and 3 deposition and decreased α-smooth muscle actin expression. Electron microscopy revealed sparse and disorganized collagen fibers in the F9-LC-treated mice. In experiments using fibroblasts, addition of a recombinant protein of the FIX light chain disrupted the typical spindle shape and alignment of fibroblasts.

CONCLUSION

F9-LC is a new candidate for use in treatments to regulate excessive fibrosis and contraction in wound healing.

siRNA-Mediated Timp1 Silencing Inhibited the Inflammatory Phenotype during Acute Lung Injury

Acute lung injury is a complex cascade process that develops in response to various damaging factors, which can lead to acute respiratory distress syndrome. Within this study, based on bioinformatics reanalysis of available full-transcriptome data of acute lung injury induced in mice and humans by various factors, we selected a set of genes that could serve as good targets for suppressing inflammation in the lung tissue, evaluated their expression in the cells of different origins during LPS-induced inflammation, and chose the tissue inhibitor of metalloproteinase Timp1 as a promising target for suppressing inflammation. We designed an effective chemically modified anti-TIMP1 siRNA and showed that Timp1 silencing correlates with a decrease in the pro-inflammatory cytokine IL6 secretion in cultured macrophage cells and reduces the severity of LPS-induced acute lung injury in a mouse model.

Scar prevention through topical delivery of gelatin-tyramine-siSPARC nanoplex loaded in dissolvable hyaluronic acid microneedle patch across skin barrier

Currently, there is no effective method to prevent the formation of hypertrophic scars and keloids, which can cause severe physical and psychological burdens to patients. Secreted protein acidic and cysteine-rich (SPARC) is involved in wound fibrosis by modulating fibroblast functions, causing excessive collagen deposition during wound healing. Thus, the reduction in SPARC gene expression after wounding can contribute to the downstream reduction in collagen production at the wound site and prevent scar formation. In this study, a dissolvable and biocompatible hyaluronic acid (HA) microneedle patch loaded with nanoplexes containing tyramine-modified gelatin and siRNA for SPARC (siSPARC/Gtn-Tyr) was investigated for topical scar prevention. Tyramine-modified gelatin (Gtn-Tyr) provides electrostatic protection and enhances cell internalization for siSPARC. In vitro studies using human dermal fibroblasts showed that both siSPARC/Gtn-Tyr nanoplexes and siSPARC/Gtn-Tyr-loaded microneedle patches can significantly reduce SPARC gene expression (P < 0.05) and do not cause discernable cytotoxic effects. Further studies using a mouse wound model demonstrate that the siSPARC/Gtn-Tyr-loaded microneedle patch can reduce collagen production during wound healing without triggering an immune response. When Gtn-Tyr-siSPARC is administered transdermally at the wound site, effective collagen reduction is achieved through silencing of the matricellular SPARC protein, thus promising the reduction of scar formation. Overall, the siSPARC/Gtn-Tyr loaded microneedle patch can potentially provide an effective transdermal anti-fibrotic treatment.

Transdermal delivery of poly-hyaluronic acid-based spherical nucleic acids for chemogene therapy

Spherical nucleic acid (SNA), as a good gene delivery system, has a good application prospect for transdermal administration in skin disorder treatment. However, most of the traditional SNA core materials are non-degradable materials, so it is worthy of further research. Herein, we report a spherical nucleic acid based on poly-hyaluronic acid (PHA) for the co-delivery of a typical chemotherapeutic drug, doxorubicin (DOX), and an antisense oligonucleotide (ASO) against the tissue inhibitor of metalloproteinases 1 (TIMP-1) for the treatment of hypertrophic scars (HS) which are caused by abnormal fibroblast proliferation. Our study showed that PHA-based SNAs simultaneously bearing TIMP-1 ASO and DOX (termed PHAAD) could significantly promote skin penetration, improve the cellular uptake, and effectively down-regulate the TIMP-1 expression and enhance the cytotoxicity of DOX. Moreover, PHAAD nanoparticles facilitated the apoptosis of hypertrophic scar cells, and reduced the burden and progression of hypertrophic scars in a xenografted mouse model without adverse side effects. Thus, our PHA-based SNA represents a new transdermal delivery vehicle for efficient combinatorial chemo and gene therapy, which is expected to treat various skin disorders.

Use of Adipose Stem Cells Against Hypertrophic Scarring or Keloid

Hypertrophic scars or keloid form as part of the wound healing reaction process, and its formation mechanism is complex and diverse, involving multi-stage synergistic action of multiple cells and factors. Adipose stem cells (ASCs) have become an emerging approach for the treatment of many diseases, including hypertrophic scarring or keloid, owing to their various advantages and potential. Herein, we analyzed the molecular mechanism of hypertrophic scar or keloid formation and explored the role and prospects of stem cell therapy, in the treatment of this condition.

Improved In Vivo Delivery of Small RNA Based on the Calcium Phosphate Method

In the past few years, we have demonstrated the efficacy of a nanoparticle system, super carbonate apatite (sCA), for the in vivo delivery of siRNA/miRNA. Intravenous injection of sCA loaded with small RNAs results in safe, high tumor delivery in mouse models. To further improve the efficiency of tumor delivery and avoid liver toxicity, we successfully developed an inorganic nanoparticle device (iNaD) via high-frequency ultrasonic pulverization combined with PEG blending during the production of sCA. Compared to sCA loaded with 24 μg of miRNA, systemic administration of iNaD loaded with 0.75 μg of miRNA demonstrated similar delivery efficiency to mouse tumors with little accumulation in the liver. In the mouse therapeutic model, iNaD loaded with 3 μg of the tumor suppressor small RNA MIRTX resulted in an improved anti-tumor effect compared to sCA loaded with 24 μg. Our findings on the bio-distribution and therapeutic effect of iNaD provide new perspectives for future nanomedicine engineering.