Prevention strategies of postoperative adhesion in soft tissues by applying biomaterials: Based on the mechanisms of occurrence and development of adhesions

A double network composite hydrogel with enhanced transdermal delivery by ultrasound for endometrial injury repair and fertility recovery

Endometrial injury and resulting female infertility pose significant clinical challenges due to the notable shortcomings of traditional treatments. Herein, we proposed a double network composite hydrogel, CSMA-RC-Zn-PNS, which forms a physical barrier on damaged tissue through photo-crosslinking while enabling sustained release of the active ingredient PNS. Based on this, we developed a combined strategy to enhance transdermal delivery efficiency using ultrasound cavitation. In vitro experiments demonstrated that CSMA-RC-Zn-PNS exhibits excellent biosafety, biodegradability, and promotes cell proliferation, migration, and tube formation, along with antioxidant and antibacterial properties. In a rat endometrial injury model, the ultrasound cavitation effect was demonstrated to enhance transdermal delivery efficiency, and the ability of CSMA-RC-Zn-PNS to promote endometrial regeneration, anti-fibrosis and fertility restoration was verified. Overall, this strategy combining CSMA-RC-Zn-PNS hydrogel and ultrasound treatment shows promising applications in endometrial regeneration and female reproductive health.

Previous maximal transurethral resection of bladder tumor lead to unfavorable perioperative outcomes following radical cystectomy

PURPOSE

To evaluate the impact of maximal transurethral resection of bladder tumor (TURBT) on perioperative outcomes following radical cystectomy (RC).

METHODS

This study included 310 patients who underwent RC for the diagnosis of bladder urothelial carcinoma. Of these, 146 patients had a history of maximal TURBT (TURBT group) and 164 did not (non-TURBT group). Patients in the TURBT group were categorized into four groups according to the time interval between the last TURBT and RC: ≤ 1 month, 1-3 months, 3-6 months, and > 6 months. Additionally, the TURBT group was stratified into a single TURBT group and multiple TURBT group. Perioperative outcomes were compared between the groups.

RESULTS

The median duration of pelvic drainage tube retention was longer in the TURBT group (11 vs. 9 days, p = 0.037). The incidence of Clavien-Dindo ≥ 3 complications (15.3% vs. 7.3%, p = 0.031) and ICU admission rate(10.4% vs. 4.5%, p = 0.048) were higher in the TURBT group. Statistically significant differences were observed in the incidence of Clavien-Dindo ≥ 3 complications (p = 0.007), reoperation rates (p = 0.041), incidence of sepsis (p = 0.022), and urinary complications (p = 0.024) across the four groups stratified by the time interval between TURBT and RC, with the 1-3 to months group demonstrating the highest incidence. There was no significant difference in perioperative outcomes between patients who underwent a single TURBT and those who underwent multiple TURBT.

CONCLUSION

Patients with a history of maximal TURBT, especially those who underwent RC within 1-3 months after maximal TURBT, have an increased risk of unfavorable perioperative outcomes following RC.

A Dual-Layer Hydrogel Barrier Integrating Bio-Adhesive and Anti-Adhesive Properties Prevents Postoperative Abdominal Adhesions

Postoperative abdominal adhesions are a common and painful complication after surgery, leading to high healthcare costs and diminished quality of life. This report presents a novel bilayer hydrogel barrier featuring an inner adhesive layer and an outer antiadhesive layer. The inner adhesive layer hydrogel (PT) is prepared by mixing polyethyleneimine (PEI) and thioctic acid (TA). The outer layer (HP) hydrogel is fabricated by the conjugation reaction of thermoresponsive zwitterionic hyaluronic acid, phenylboronic acid, and epigallocatechin gallate complex and polyvinyl alcohol based on dynamic boronic ester bond. The PEI/TA layer enhances attachment to moist tissue surfaces in vivo, and the anti-adhesive layer HP hydrogel promotes biocompatibility and anti-inflammation while minimizing protein adsorption and improving mechanical stability. The bilayer hydrogel (HPPT) exhibited rapid gelation, robust adhesion in dynamic and moist environments, superior viscoelastic properties and cellular biocompatibility. A mouse-cecum abdominal wall adhesion model is utilized to evaluate efficacy, and the HPPT hydrogel shows local retention, anti-inflammatory effect, and inhibits fibrin deposition while minimizing adhesion formation. These findings highlight the innovative structural and functional properties of the HPPT hydrogel, positioning it as a promising therapeutic barrier in peritoneal surgery aimed at reducing postoperative adhesions and enhancing surgical outcomes.

An anti-inflammatory and anti-fibrotic Janus hydrogel for preventing postoperative peritoneal adhesion

Postoperative peritoneal adhesion (PPA) is pathological tissue hyperplasia between surgical wounds and nearby organs. Currently, traditional double-sided bioadhesives are limited in preventing PPA due to the indiscriminate adhesive properties and the poor interaction with wet tissues. Herein, we developed a Janus hydrogel, named PAA-Cos, by using the polycationic carbohydrate polymer of chitooligosaccharide (Cos) and the polyanionic polymer of polyacrylic acid (PAA). The adhesive layer of Janus hydrogels could adhere to wet tissue tightly due to surfaces composed of carboxyls, and the positively charged biomaterial (Cos) neutralized carboxyls on one side of PAA hydrogel to form Janus hydrogels. Moreover, PAA-Cos can further load with ligustrazine hydrochloride (Ligu), a pharmaceutical compound with anti-inflammatory and anti-fibrotic effects, finally obtaining PAA-Cos@Ligu. After the application of PAA-Cos@Ligu on the surgical trauma, the bottom surface can adhere to wet tissues robustly to restore the wound, while the top surface acts as a physical barrier with antiadhesive effects to avoid PPA. PAA-Cos@Ligu also exhibited anti-inflammatory effects by promoting M2 macrophage polarization, inhibiting the myofibroblast-like differentiation of peritoneal mesothelial cells, and blocking the TGF-β/Smad2/3 signaling pathway to hinder collagen deposition. Our findings suggest that PAA-Cos@Ligu has great potential as an anti-adhesion candidate with biocompatibility and ease of preparation.

Topical administration of tranexamic acid for prevention of postoperative epidural fibrosis: insights from a rabbit laminectomy model

Significant advancements in imaging and surgical methodologies have led to more frequent performance of neurosurgical procedures such as laminectomy in both animal and human patients. Epidural fibrosis (EF) is defined as the excessive formation of scar tissue in the epidural space after lumbar laminectomy, often resulting in recurring postoperative pain. Given the association between postoperative hematoma accumulation at the laminectomy site and the development of EF, the present study aimed to evaluate the preventive impact of tranexamic acid (TXA), an antifibrinolytic agent with well-recognized hemostatic properties across various surgical fields. A rabbit laminectomy model was constructed to assess its effectiveness in reducing EF formation. A total number of 18 adult New Zealand White male rabbits were randomly divided into two groups: The control (saline) group and the treatment (topical TXA) group. Each rabbit underwent a two-level laminectomy at L3-L4. The treatment group received 5.00 mL of 100 mg mL-1 TXA solution applied topically to the laminectomy site, while the control group received 5.00 mL of saline. Postoperative evaluations included magnetic resonance imaging at week six to assess EF, followed by histopathological examinations to evaluate fibroblast cell density in scar tissue, EF grading and thickness of the dura mater. The analysis of magnetic resonance imaging and histopathologic data revealed significant differences between the two groups indicating that topical administration of TXA might be a promising approach for preventing EF.

Impact of leptin on postoperative peritoneal adhesion formations in colorectal resection

PURPOSE

Postoperative peritoneal adhesion formation (PAF) is a distressing complication. Leptin, secreted by fat tissues, may be associated with PAF. However, the relationships between PAF and leptin are unclear. This study investigated the impact of leptin on PAF after colorectal tumor resection.

METHODS

A cecum cauterization mouse model was used to investigate PAF and its association with leptin. Mice adhesion score (AS) was evaluated on day 7 after treatment. The clinical study included patients who underwent elective colorectal resection with temporary ileostomy between April 2021 and December 2024. The AS was evaluated at the time of ileostomy closure. Patients with the highest AS quartile were classified into the high-AS group; clinical factors associated with PAF were examined. An enzyme-linked immunosorbent assay was used to measure human and murine serum leptin concentrations.

RESULTS

The animal experiment revealed that serum leptin levels on postoperative day 7 were negatively correlated with mice ASs (P = 0.0043, r = -0.6241). In a clinical study, eight patients had a high AS (27.6%). Visceral fat mass and preoperative serum leptin levels were higher in the high-AS group than in the low-AS group. The serum leptin ratio (postoperative value to preoperative value) on postoperative day 7 was lower in the high-AS group. In multivariate analysis, the serum leptin ratio was an independent factor for classifying into the high-AS group.

CONCLUSIONS

A decrease in postoperative serum leptin levels was associated with severe PAF. Leptin may be a novel key molecule in PAF.

Janus decellularized membrane with anisotropic cell guidance and anti-adhesion silk-based coatings for spinal dural repair

The repair of soft tissues with anisotropic structures, such as spinal dura mater, requires the use of biomaterials to guide tissue directional growth while minimizing epidural fibrotic adhesion. Herein, we construct the Janus small intestinal submucosa (SIS) via silk-based hydrogel coatings, which provides extracellular matrix-mimicking features and anti-adhesion performance for spinal dural defect repair. We demonstrate that the silk fibroin and methacrylated silk fibroin (SilMA) composite microgroove hydrogel coating at the inner surface via water vapor annealing treatment exhibits excellent structure stability, stable attachment to SIS substrate, and shows orientated cell morphology and extracellular matrix produced by fibroblasts, good histocompatibility and promotes the polarization of macrophages towards the anti-inflammatory phenotype. The methacrylated hyaluronic acid and SilMA composite coating outer surface serves as favorable physical barrier shows effective resistance to protein adsorption, cell and tissue adhesion, and can mitigate fibrosis reactions. Spinal dura mater defect experiments on male rats demonstrate that the Janus SIS simultaneously promotes dural regeneration and inhibits epidural fibrosis.

Radiotherapy plus a self-gelation powder encapsulating tRF5-GlyGCC inhibitor potentiates natural kill cell immunity to prevent hepatocellular carcinoma recurrence

Hepatocellular carcinoma (HCC) recurrence postresection represents a thorny problem in clinical practice, of which impaired natural killer (NK) cell cytotoxicity represents one of crucial causes. Apart from recurrence, hepatectomy-induced abdominal adhesion also poses huge clinical challenges such as abdominal pain, intestinal obstruction, and perforation. Evidence demonstrates that radiotherapy can upregulate NK group 2D ligand expression on tumor cells to enhance NK cell cytotoxicity, indicating its great potential of curbing HCC recurrence. Nevertheless, radiotherapy has also been disclosed to incur suppression on NK antitumor cell immunity. Herein, we reveal that glycocholic acid (GCA)/tRNA-derived fragment 5 (tRF5)-GlyGCC signaling axis is activated in mouse HCC model after radiotherapy, which dampens NK cell antitumor immunity to limit therapeutic efficacy. Mechanistically, tRF5-GlyGCC can interact with KDM6B to epigenetically upregulate Runx2 and then transcriptionally activate ITGBL1 and S100A9 expression in HCC cells, which further reduces NK cell cytotoxicity directly and attracts myeloid-derived suppressor cell (MDSC) to inhibit NK cell function indirectly, respectively. Therefore, radiotherapy plus targeting tRF5-GlyGCC may be an optimized postoperative adjuvant therapy against HCC recurrence. Then, a nanocomposite powder is designed for liver-localized delivery of tRF5-GlyGCC inhibitor. After sprayed to liver resection margin of mouse HCC model, this powder can rapidly form an in-situ Janus-adhesive hydrogel, which allows for sustained delivery of tRF5-GlyGCC inhibitor. Importantly, it can synergize with radiotherapy to potentiate NK cell antitumor immunity and prevent HCC recurrence postresection. Moreover, its application to surgical bed also effectively mitigates abdominal adhesion in a rat hepatectomy model. Altogether, our work develops a tRF5-GlyGCC-targeting nanocomposite power for sensitizing radiotherapy to thwart HCC recurrence and preventing abdominal adhesion.

Tackling the Problem of Tendon Adhesions: Physical Barriers Prepared from α-Amino Acid-Based Poly(ester amide)s

In this work, electrospun membranes of α-amino acid based poly(ester amide)s (AAA-PEAs) from L-alanine (PEA_ala) or L-phenylalanine (PEA_phe) were successfully prepared to be used as physical barriers in the orthopedic field. Also, blends of these two polymers were used in different weight ratios (25:75, 50:50 and 75:25) to obtain physical barriers with different properties. All membranes had a suitable pore size to prevent fibroblast infiltration, and their porosity and permeability values were in a range that allowed the passage of nutrients. The membrane made from a blend of 25%wt of PEA_ala and 75% wt of PEA_phe showed the highest value of swelling capacity, suggesting a higher lubricant feature. The same membrane suffered a more pronounced degradation, as evidenced by the in vitro enzymatic degradation tests. All membranes showed suitable toughness values, a crucial property with regard to application. In vitro cytotoxicity tests performed with a NIH3T3 fibroblast cell line revealed decreased cell viability after 7 days, suggesting that these membranes are not ideal substrates to promote fibroblast adhesion and proliferation. These membranes as physical barriers represent a significant advance in the field given the limited literature on electrospun AAA-PEAs and their use to prevent tendon adhesion.

Herbal HuoXueTongFu Formula with anti-inflammatory and fibrinolytic activity regulation for the prevention of postoperative peritoneal adhesions

Background

The HuoXueTongFu Formula (HXTF) originates from the classic prescription "DaHuangMuDan Decoction" from the "Synopsis of the golden chamber". Our previous study revealed that HXTF has a positive effect on postoperative peritoneal adhesion (PPA). However, the specific mechanism of HXTF on PPA formation within the time-to-treatment window has not been fully elucidated. This study aimed to determine the critical roles of HXTF as a result of its specific anti-inflammatory and antifibrinolytic activities for PPA treatment.

Methods

The eight main bioactive components of HXTF were subjected to high-performance liquid chromatography-mass spectrometry. The core targets, critical biological processes, and underlying pathways of HXTF and PPA were identified via a series of network pharmacological methods. The specific anti-inflammatory function in the initial step of PPA formation was validated in peritoneal macrophages (PMs) isolated from PPA mice on Day 3 postsurgery. The potential anti-fibrinolytic activity in the next stage of PPA formation was subsequently explored in PPA mice on Day 7 postsurgery.

Results

Network pharmacology revealed 160 common targets between HXTF and PPA. Several core targets, i.e., matrix metalloproteinase 9 (MMP9), tissue-type plasminogen activator (tPA), and plasminogen activator inhibitor 1 (PAI-1), were annotated as important biological processes (extracellular matrix disassembly and the collagen catabolic process). Validation experiments revealed that HXTF could induce macrophage polarization-mediated anti-inflammatory reactions by increasing the phagocytic capacity of PMs and promoting the release of anti-inflammatory cytokines (IL-4 and IL-10). In addition, HXTF promoted fibrinogenolysis and improved fibrinolytic activity, thereby inhibiting collagen deposition and reducing adhesion development.

Conclusion

The ameliorative effects of herbal HXTF on PPA formation are attributable to the induction of macrophage polarization-mediated anti-inflammatory reactions in the early stage of PPA formation and the promotion of fibrinogenolysis and fibrinolytic activity in the middle stage of PPA formation. HXTF may be a promising alternative agent for the prevention and treatment of PPA.

An In Situ UV Cross-Linking Asymmetric Adhesive Hydrogel for Noncompressible Hemostasis and Postoperative Adhesion Prevention

Noncompressible hemorrhage control is vital for clinical outcome after surgical treatment and prehospital trauma injuries. Meanwhile, wound bleeding and tissue damage could induce postoperative adhesions, leading to a severe threat to the health of patients. Considerable research had been conducted on the development of hemostatic and antiadhesive materials. However, it was still a great challenge to realize hemostasis and antiadhesion simultaneously especially in inaccessible and irregular wound sites. In this study, a kind of fluid hemostatic agent composed of gelatin methacryloyl/sulfobetaine methacrylate/oxidized konjac glucomannan (termed GOS) was developed, which spread immediately upon contacting the hepatic trauma surface and turned into hydrogels under UV radiation within 5 s, resulting in rapid hemostasis and firm adhesion to tissues (shear strength 486.08 kPa). Importantly, the surface of the as-formed GOS hydrogel exhibited lubricious and nonadhesive properties, exhibiting excellent anti-postoperative adhesion performance in a rat liver hemostasis model and a rat abdominal wall-cecum adhesion model. In addition, the GOS hydrogel reduced the postoperative secretion of inflammatory factors TNF-α and IL-6, facilitating the tissue repair. Therefore, the asymmetrical adhesive GOS hydrogel could fulfill the requirements for simultaneously rapid hemostasis, tissue adhesion, and subsequent excellent antiadhesion, which demonstrated significant potential for diverse clinical surgical operation scenarios.

A "Janus" Zwitterionic Hydrogel Patch for Tissue Repair and Prevention of Post-Operative Adhesions

Anti-peritoneal adhesions (PA) are very important after abdominal surgery for that PA often leads to other medical problems and imposes a huge financial burden on the national healthcare system. In this work, a "Janus" zwitterionic hydrogel patch where one side can adhere firmly to the tissue, while the other side has anti-fouling properties and has little interaction with the surrounding tissue has been developed. The "Janus" hydrogel patch is prepared by in situ formation of a bonding polymer layer poly(acrylic-co-N-hydroxysuccinimide acrylate) on one side of zwitterionic hydrogel. The mechanical, swelling, adhesion, biodegradability and biocompatibility tests are performed to study the function of "Janus" hydrogel patch to prevent wound adhesion and rapid repair. It is found that the adhesive side of the hydrogel patch has stable adhesion to tissues, avoiding the slippage faced by many commercial anti-adhesion gels in the body. The other zwitterionic side can resist proteins and fibroblasts and prevent external interactions or adhesion with other tissues. This convenient and effective method provides a new idea for the design of postoperative anti-adhesion materials and broadens the application of hydrogels in the biomedical field.

Chitosan-Alginate Hydrogel Enriched with Hypericum perforatum Callus Extract for Improved Wound Healing and Scar Inhibition

Hypericum perforatum callus contains pluripotent stem cells, and its extract (HPCE) is a natural compound that includes various biologically active components, such as phenolic acids, flavonoids, and naphthodiantrons like hypericin and hyperforin. These components give HPCE significant antibacterial and antioxidant properties, making it a valuable option for wound healing. Unlike traditional wound dressings that may leave a residue or necessitate invasive procedures like phototherapy, HPCE is a promising alternative. This study presents a hydrogel wound dressing made from a chitosan/alginate scaffold loaded with HPCE (CA/HPCE). This system displayed remarkable mechanical properties coupled with a high swelling capacity. Moreover, it demonstrated potent antibacterial, antioxidant, and anti-inflammatory activities, promoting a favorable environment for wound healing. In vitro studies confirmed that our wound dressings effectively inhibited Escherichia coli (E. coli) and drug-resistant bacteria like Klebsiella pneumoniae (K. pneumoniae), methicillin-resistant Staphylococcus aureus (MRSA), and methicillin-resistant coagulase-negative Staphylococcus (MR-CoNS). Additionally, CA/HPCE had the potential to significantly augment fibroblast migration. Moreover, in vivo investigations confirmed that this system accelerated re-epithelialization, neovascularization, and collagen deposition while reducing inflammation. Immunohistochemistry (IHC) analysis of α-smooth muscle actin (α-SMA) indicated the absence of hypertrophic scar formation postdressing. These findings suggest that CA/HPCE is a highly effective and innovative solution for advanced wound care.

Enhanced Biodegradation of Silk Fibroin Hydrogel for Preventing Postoperative Adhesion

An absorbable adhesion barrier is a medical device that prevents postoperative adhesion and matches its biodegradation time with the regeneration period of its target tissues, which is important for antiadhesion effects. Physical hydrogels of Bombyx mori silk fibroin (SF) proteins are degradable in vivo. However, their biodegradation time is too long to exert antiadhesion effects. To shorten the biodegradation time of the SF hydrogels, we decreased the molecular weight (MW) of the SF proteins by alkaline treatment and prepared low-MW (LMW) SF hydrogels. The hydrogels contained less β-sheet crystalline and more amorphous structures than conventional, high-MW (HMW) SF hydrogels. Because of the potential loosened SF molecular structures in the hydrogel networks, the LMW SF hydrogels showed enhanced biodegradation (i.e., shorter in vitro enzymatic biodegradation time and faster in vivo biodegradation rate) as well as a lower affinity for plasma proteins and fibroblasts, which are involved in postoperative adhesion formation. An antiadhesion test using a rat abdominal adhesion model demonstrated that the LMW SF hydrogel applied to the abraded cecum was almost completely degraded within two weeks postimplantation, with a significantly lower adhesion severity score than that in the untreated model rat group. Conversely, the HMW SF hydrogel remained between the cecum and abdominal wall, with the same adhesion severity as that of the untreated model rat group. Therefore, we concluded that the antiadhesion effects of SF hydrogels were induced by enhanced biodegradation. The results of this study indicate the potential of LMW SF hydrogels as absorbable adhesion barriers.

Engineered Lubricative Lecithin-Based Electrospun Nanofibers for the Prevention of Postoperative Abdominal Adhesion

Background: Postoperative abdominal adhesion is a prevalent complication following abdominal surgery, with the incidence of adhesion reaching up to 90%, which may precipitate a range of adverse outcomes. Although fibrous membranes loaded with various anti-inflammatory or other drugs have been proposed for anti-adhesion, most of them suffer from drug-induced adverse effects. Methods: In this study, a lecithin-based electrospun polylactic acid (PLA) nanofibrous membrane (L/P-NM) was developed for the prevention of postoperative abdominal adhesion, utilizing the hydration lubrication theory. The loaded zwitterionic lecithin allows the nanofiber surface to strongly bind water molecules to create a hydration lubrication interface. Results: As the TGA results show, the content of bound water in the nanofibers increased significantly with the increase in the lecithin content. Tribological test results show that L/P-NM reached a minimum coefficient of friction (COF) of about 0.112. Additionally, the developed nanofibrous membranes possess favorable tensile property and biocompatibility. Rat postoperative abdominal adhesion model evaluation results demonstrated that L/P-NM possesses significant anti-adhesive performance, with an adhesion score of only 1. Conclusions: Therefore, this study offers a promising strategy for efficiently preventing abdominal adhesion.

Bioinspired Asymmetric-Adhesion Janus Hydrogel Patch Regulating by Zwitterionic Polymers for Wet Tissues Adhesion and Postoperative Adhesion Prevention

Asymmetrically adhesive hydrogel patch with robust wet tissue adhesion simultaneously anti-postoperative adhesion is essential for clinical applications in internal soft-tissue repair and postoperative anti-adhesion. Herein, inspired by the lubricative role of serosa and the underwater adhesion mechanism of mussels, an asymmetrically adhesive hydrogel Janus patch is developed with adhesion layer (AL) and anti-adhesion layer (anti-AL) through an in situ step-by-step polymerization process in the mold. The AL exhibits excellent adhesion to internal soft-tissues. In contrast, the anti-AL demonstrated ultralow fouling property against protein and fibroblasts, which hinders the early and advanced stages of development of the adhesion. Moreover, the Janus patch simultaneously promotes tissue regeneration via ROS clearance capability of catechol moieties in the AL. Results from in vivo experiments with rabbits and rats demonstrate that the AL strongly adheres to traumatized tissue, while the anti-AL surface demonstrate efficacy in preventing of post-abdominal surgery adhesions in contrast to clinical patches. Considering the advantages in terms of therapeutic efficacy and off the shelf, the Janus patch developed in this work presents a promise for preventing postoperative adhesions and promoting regeneration of internal tissue defects.

Microenvironment-Responsive Hydrogel Enclosed with Bioactive Nanoparticle for Synergistic Postoperative Adhesion Prevention

Postoperative adhesion (PA) is a severe complication of abdominal surgery caused by the inability of clinical physical barriers to cope with diverse pathological factors in the process of PA formation. Herein, we described a multifunctional hydrogel composed of bioactive nanoparticles (BNs) and dual-responsive hydrogel to serve as a combination of physical and pharmacological therapy for preventing PA. Specifically, BNs with pro-inflammatory cell-targeted aggregation were designed by integrating hyaluronic acid onto the polydopamine (PDA)-coated hollow ZrO2 nanoparticles loaded with antimicrobial peptides and platelet lysates that can eliminate bacterial infection and promote tissue repair. PDA can remove the excessive reactive oxygen species (ROS) and thus suppress the oxidative stress damage and accompanying inflammation in the presence of high ROS. The dynamically cross-linked host hydrogel presents injectable yet microenvironment-responsive properties, which enables complete coverage of the uneven tissue and instantly forms a physical barrier to effectively isolate injured tissues and neighboring organs, and synchronously acts as a niche to deliver the BNs in a controlled way. The hydrogel demonstrates a remarkable antiadhesion effect in a rat cecum-abdominal wall adhesion model. Together, this "all-in-one" composite hydrogel strategy capable of a physical barrier capability and pharmacological effects represents a promising clinical solution to prevent PA.

Construction of a Curcumin‐Loaded PLLA/PCL Micro‐Nano Conjugated Fibrous Membrane to Synergistically Prevent Postoperative Adhesion From Multiple Perspectives

Postoperative adhesion (POA) has emerged as a prevalent clinical challenge in soft tissue repair, emphasizing the critical need for preventive measures. However, the complex POA development process makes POA prevention from a single aspect insufficient. Hence, a curcumin‐loaded poly‐L‐lactic acid‐poly (caprolactone) micro‐nano conjugated fibrous membrane (PAPC MCFM (cur)) is engineered to synergistically prevent POA from multiple perspectives, in which poly (caprolactone) (PCL) nanofibers (118 ± 12 nm) with low orientation traverse the oriented poly‐L‐lactic acid (PLLA) microfibers (2.0 ± 0.3 µm). The PAPC MCFM not only significantly improves the mechanical properties of the anisotropic fibrous membrane (AIFM) that the modulus of elasticity and the tensile strength in the direction vertical to microfiber orientation increase by 4.5 and 13.0 times, respectively, but also can further enhance the “contact guidance effect” of AIFM, i.e., hindering fibroblast adhesion, proliferation, and differentiation to myofibroblast through inhibiting integrin β1 activation, vinculin expression and focal adhesion (FA) formation, and the nuclear localization activation of yes‐associated protein (YAP). Except for these effects, PAPC MCFM loading with 2.5 mg mL−1 curcumin can further prevent POA by delivering anti‐inflammatory, antioxidant, and antibacterial properties, and by suppressing fibrosis through decreased transforming growth factor‐β1(TGF‐β1) expression, showing effective POA prevention in rat abdominal cavity and rabbit dura mater models.

A biodegradable shape memory polyurethane film as a postoperative anti-adhesion barrier for minimally invasive surgery

Postoperative adhesions commonly form in various tissues, resulting in serious implications and an increased risk of secondary surgery. The application of anti-adhesion films as physical barriers has proven effective in reducing adhesion incidence and severity. However, existing anti-adhesion films require manual deployment during minimally invasive surgery, posing inconvenience and possibility of further injury. To address these limitations, we have developed an intelligent anti-adhesion film based on shape memory polyurethane. In this work, a linear shape memory polyurethane (ISO2-PU), incorporating hexamethylene isocyanate and isosorbitol as hard segments and poly(D, L-lactic acid) macrodiol as soft segments, was fabricated into an anti-adhesion film. The favorable shape memory effect of the ISO2-PU film ensures its convenient delivery and automatic unfolding, as revealed by a simulation experiment for endoscopic surgical implantation. Furthermore, the glass transition temperature (Tg) close to body temperature endows the ISO2-PU film with good mechanical compliance, thus ensuring a reliable fit with the wounded tissue to avoid undesired folding. Finally, in vivo experiments using a rat cecal abdominal wall injury model demonstrated that the combination of reliable fit, appropriate degradation rate, and good cytocompatibility promises the ISO2-PU film with high anti-adhesion efficacy. This work validates the concept of shape memory anti-adhesion barrier and expands future directions for advanced anti-adhesion biomaterials. STATEMENT OF SIGNIFICANCE: Postoperative adhesions are a common complication that occurs widely after various surgeries. This work developed an intelligent anti-adhesion film based on a linear shape memory polyurethane (ISO2-PU). This film is featured with remarkable shape memory effect and mechanical compliance at body temperature, appropriate degradability, and good cytocompatibility. These merits ensure convenient delivery and smart unfolding of ISO2-PU film during minimally invasive surgery and favorable postoperative anti-adhesion efficacy. The results validate the concept of shape memory anti-adhesion barrier and paves a way for designing next-generation anti-adhesion biomaterials.

The Toll-like receptor 4 antagonist TAK-242 in combination with sodium hyaluronate alleviates postoperative abdominal adhesion in a mouse model

Postoperative abdominal adhesion is one of the most common complications after abdominal surgery. The Toll-like receptor 4 (TLR4) signaling pathway is one of the most common inflammation-related pathways, and it has been demonstrated that TLR4 is highly expressed in adhesive tissues; however, the function of TLR4 in adhesion formation has not yet been studied. In the present study, the expression of TLR4 was first detected by immunohistochemical (IHC) and double-immunofluorescence staining in 40 mice, which were randomly divided into four groups, and sacrificed at 1, 3, 5 and 7 days after surgery. Subsequently, another 40 mice were randomly divided into five groups; with the exception of the sham group, the other groups were modeled and treated with saline that contained DMSO, sodium hyaluronate (HA), TAK-242 or TAK-242 + HA (applied to damaged peritoneal wounds). A total of 7 days after surgery, the mice were sacrificed and specimens were collected. Inflammation was detected by hematoxylin and eosin staining, and ELISA of transforming growth factor- β1 (TGF-β1) and interleukin-6 (IL-6); collagen deposition was examined by Masson staining and IHC staining of α-SMA; and reactive oxygen species (ROS) were detected by ROS staining and malondialdehyde (MDA) assay. The results revealed that TLR4 was highly expressed in the adhesive tissues at 3, 5 and 7 days after surgery. In addition, TAK-242 + HA treatment could reduce abdominal adhesion formation, exhibiting lower Nair's score and inflammation scores, lower TGF-β1 and IL-6 levels, and lower collagen thickness and α-SMA levels compared with those in the control group. In addition, the TAK-242 + HA group had lower levels of ROS and MDA compared with those in the control group. The present study revealed that TLR4 was highly expressed in the process of adhesion formation and its inhibitor, TAK-242, combined with HA, could reduce adhesion formation by reducing inflammation and ROS, and alleviating collagen deposition.

[Experimental study on repairing rat abdominal wall defect with chitosan hydrogel/polypropylene mesh composite]

OBJECTIVE

To investigate the improvement effects and mechanisms of composite chitosan (CS) hydrogel on traditional polypropylene (PP) mesh for repairing abdominal wall defects.

METHODS

CS hydrogel was prepared via physical cross-linking and then combined with PP mesh to create a CS hydrogel/PP mesh composite. The internal structure and hydrophilicity of the composite were characterized using macroscopic observation, upright metallographic microscope, scanning electron microscopy, and water contact angle measurements. The performance of the composite (experimental group) in resisting cell adhesion and supporting cell infiltration was assessed through fibroblast (NIH-3T3) infiltration experiments and human umbilical vein endothelial cells (HUVECs) tube formation assays, and simple cells were used as control group. Finally, a bilateral abdominal wall defect model (1.5 cm×1.0 cm) was established in 18 Sprague Dawley rats aged 8-10 weeks, with the composite used on one side (experimental group) and PP mesh on the other side (control group). The effects on promoting wound healing, preventing adhesion, angiogenesis, and anti-inflammation were investigated through macroscopic observation, histological staining (HE and Masson staining), and immunohistochemical staining (CD31, CD68).

RESULTS

The composite appeared as a pale yellow, transparent solid with a thickness of 2-3 mm, with the PP mesh securely encapsulated within the hydrogel. Scanning electron microscopy revealed that the hydrogel contained interconnected pores measuring 100-300 μm, forming a porous structure. Contact angle measurements indicated that CS hydrogel exhibited good hydrophilicity, while PP mesh was highly hydrophobic. In vitro cell culture experiments showed that DAPI staining indicated fewer positive cells in the experimental group after 1 day of culture, while the cells in control group covered the entire well plate. After 3 days of culture, the cells in experimental group were spherical and displayed uneven fluorescence, suggesting that the material could reduce cell adhesion while supporting cell infiltration. HUVECs tube formation experiments demonstrated an increase in cell numbers in experimental group with a trend towards tube formation, while cells in control group were sparsely distributed and showed no migration. In the rat abdominal wall defect repair experiment, results showed that after 1 week post-surgery, the experimental group had tissue and blood vessels infiltrating, and by 4 weeks, the integrity was well restored with significant regeneration of muscle and blood vessels, while the control group exhibited adhesions and incomplete healing. HE staining results indicated weaker cell infiltration in the experimental group, with cell density significantly higher than that of the control group at 2 and 4 weeks post-surgery ( P<0.05). Masson staining revealed that collagen fibers in the experimental group were arranged neatly, with significantly increased collagen content at 2 weeks post-surgery ( P<0.05), while collagen content was similar in both groups at 4 weeks ( P>0.05). Immunohistochemical staining showed that CD31-positive cells were evenly distributed between muscle layers in the experimental group, whereas the control group exhibited notable defects. At 2 weeks after operation, the CD31-positive cell ratio was significantly higher than that in the control group ( P<0.05); at 2 and 4 weeks after operation, the CD68-positive cell ratio in the experimental group was significantly lower than that in the control group ( P<0.05).

CONCLUSION

CS hydrogel has a positive effect on preventing adhesions and promoting wound healing, exhibiting anti-inflammatory and pro-angiogenic properties during the healing process. This provides a promising strategy to address challenges related to abdominal adhesions and reconstruction.

Long-Term Efficacy and Safety of Adhesion Prevention Agents in Abdominal and Pelvic Surgeries: A Systematic Review

This systematic review evaluates the long-term efficacy and safety of adhesion prevention agents in abdominal and pelvic surgeries, synthesizing data from randomized controlled trials and meta-analyses. Adhesions, common postoperative complications, can lead to significant morbidity, including chronic pain, infertility, and bowel obstruction. Various agents, including hyaluronic acid-carboxymethylcellulose films and icodextrin solutions, have been developed to mitigate these risks. Our review highlights that agents like bioresorbable membranes (Seprafilm) and icodextrin significantly reduce the incidence and severity of adhesions, particularly in high-risk surgeries. However, certain complications such as anastomotic leaks and infections are associated with some agents, emphasizing the need for careful consideration in clinical decision-making. Additionally, while these agents reduce postoperative morbidity and enhance recovery, further research is needed to assess their long-term impact, particularly regarding fertility outcomes and chronic pain. This review underscores the importance of integrating adhesion prevention agents into surgical protocols, which has the potential to reduce healthcare costs, improve patient outcomes, and optimize postoperative care pathways. Standardization of adhesion prevention practices could further enhance surgical efficiency and patient recovery, particularly in high-risk patient populations and complex surgeries.

Shaping the immune landscape: Multidimensional environmental stimuli refine macrophage polarization and foster revolutionary approaches in tissue regeneration

In immunology, the role of macrophages extends far beyond their traditional classification as mere phagocytes; they emerge as pivotal architects of the immune response, with their function being significantly influenced by multidimensional environmental stimuli. This review investigates the nuanced mechanisms by which diverse external signals ranging from chemical cues to physical stress orchestrate macrophage polarization, a process that is crucial for the modulation of immune responses. By transitioning between pro-inflammatory (M1) and anti-inflammatory (M2) states, macrophages exhibit remarkable plasticity, enabling them to adapt to and influence their surroundings effectively. The exploration of macrophage polarization provides a compelling narrative on how these cells can be manipulated to foster an immune environment conducive to tissue repair and regeneration. Highlighting cutting-edge research, this review presents innovative strategies that leverage the dynamic interplay between macrophages and their environment, proposing novel therapeutic avenues that harness the potential of macrophages in regenerative medicine. Moreover, this review critically evaluates the current challenges and future prospects of translating macrophage-centered strategies from the laboratory to clinical applications.

Light-Operated Transient Unilateral Adhesive Hydrogel for Comprehensive Prevention of Postoperative Adhesions

Dislocation of anti-adhesion materials, non-specific tissue adhesion, and the induction of secondary fibrinolysis disorders are the main challenges faced by postoperative anti-adhesion materials. Herein, a self-leveling transient unilateral adhesive hydrogel is custom-designed to conquer these challenges with a theoretically calculated and dual-step tailored gellan gum (GG) as the sole agent. First, the maximum gelation temperature of GG is lowered from 42-25 °C through controlled perturbation of intra- and inter-molecular hydrogen bonds, which is achieved by employing the methacrylic anhydride as a "hydrogen bond's perturbator" to form methacrylate GG (MeGG). Second, the "self-leveling" injectability and wound shape adaptably are endowed by the formation of borate-diol complexed MeGG (BMeGG). Finally, the transient unilateral tissue-adhesive hydrogel (BMeGG-H) barrier is prepared through photo-controlled cross-linking of reactive alkenyl groups. This degradable hydrogel demonstrates favorable rheological properties, light-controlled unilateral adhesion properties, biocompatibility, anti-fibrin adhesion, and anti-cell adhesion properties in vitro. Comprehensive regulation of the fibrinolysis balance toward non-adhesion is conformed in a rat model after intra-abdominal surgery via anti-autoinflammatory response, intestinal wall integrity repair, and Tissue plasminogen activator (t-PA) and plasminogen activator inhibitor-1 (PAI-1) balance adjustment. Notably, the 14th day anti-adhesion effective rate is 100%, indicating its significant potential in clinical applications for postoperative anti-adhesion.

Intra-peritoneal lavage of Zingiber officinale rhizome and its active constituent gingerol impede inflammation, angiogenesis, and fibrosis following post-operative peritoneal adhesion in male rats

Post-operative peritoneal adhesions (PA) are a common and important clinical problem. In this study, we focused on the ameliorative efficacy of ginger and gingerol compounds on surgical-induced peritoneal adhesion, and their strategies that disrupted the PA formation pathways to suppress their incidence. First, liquid chromatography-mass spectrometry (LC-MS) was established to separate and identify several chemical groups of ginger rhizome extract. In the next steps, male Wistar albino rats were randomly selected and divided into various groups, namely sham, control, ginger extract (0.6, 1.8, 5 %w/v), and gingerol (0.05, 0.1, 0.3, and 1 %w/v). Finally, we investigated the macroscopic parameters such as wound healing, body weight as well as spleen height and weight. In addition, visual peritoneal adhesion assessment was performed via Nair et al and Adhesion Scoring Scheme. Moreover, the microscopic parameters and biological assessment was performed via and immunoassays. The present findings revealed significant improvement in wound healing and reduction of the adhesion range, as Nair et al. and Adhesion Scoring Scheme scoring, in both the ginger and gingerol groups compared to the PA group (P < 0.05). Whereas, gingerol (0.3 % w/v) was able to increase the body weight in rats (P < 0.0001) at end stage of experiment. Also, inflammation, angiogenesis, and fibrosis were significantly decreased due to the downregulation of interleukin (IL)-6, tumor necrosis factor (TNF)-α, transforming growth factor (TGF)-β1, vascular endothelial growth factor (VEGF), respectively, in the ginger and gingerol groups compared to the PA group (P < 0.05). In contrast, the levels of IL-10 were increased in the ginger and gingerol groups compared to the control group (P < 0.01). Our results proved that ginger rhizome and gingerol, as novel therapeutic compounds, could be used to prevent PA for their beneficial anti-inflammatory as well as anti-fibrosis properties in clinical trials. However, further clinical studies are required to approve the effectiveness of ginger and gingerol.

Janus Nanofibrous Patch with In Situ Grown Superlubricated Skin for Soft Tissue Repair with Inhibited Postoperative Adhesion

The patch with a superlubricated surface shows great potential for the prevention of postoperative adhesion during soft tissue repair. However, the existing patches suffer from the destruction of topography during superlubrication coating and lack of pro-healing capability. Herein, we demonstrate a facile and versatile strategy to develop a Janus nanofibrous patch (J-NFP) with antiadhesion and reactive oxygen species (ROS) scavenging functions. Specifically, sequential electrospinning is performed with initiators and CeO2 nanoparticles (CeNPs) embedded on the different sides, followed by subsurface-initiated atom transfer radical polymerization for grafting zwitterionic polymer brushes, introducing superlubricated skin on the surface of single nanofibers. The poly(sulfobetaine methacrylate) brush-grafted patch retains fibrous topography and shows a coefficient of friction of around 0.12, which is reduced by 77% compared with the pristine fibrous patch. Additionally, a significant reduction in protein, platelet, bacteria, and cell adhesion is observed. More importantly, the CeNPs-embedded patch enables ROS scavenging as well as inhibits pro-inflammatory cytokine secretion and promotes anti-inflammatory cytokine levels. Furthermore, the J-NFP can inhibit tissue adhesion and promote repair of both rat skin wounds and intrauterine injuries. The present strategy for developing the Janus patch exhibits enormous prospects for facilitating soft tissue repair.

Nanofiber Hydrogel Drug Delivery System for Prevention of Postsurgical Intestinal Adhesion

Intestinal adhesion is one of the complications that occurs more frequently after abdominal surgery. Postsurgical intestinal adhesion (PIA) can lead to a series of health problems, including abdominal pain, intestinal obstruction, and female infertility. Currently, hydrogels and nanofibrous films as barriers are often used for preventing PIA formation; however, these kinds of materials have their intrinsic disadvantages. Herein, we developed a dual-structure drug delivery patch consisting of poly lactic-co-glycolic acid (PLGA) nanofibers and a chitosan hydrogel (NHP). PLGA nanofibers loaded with deferoxamine mesylate (DFO) were incorporated into the hydrogel; meanwhile, the hydrogel was loaded with anti-inflammatory drug dexamethasone (DXMS). The rapid degradation of the hydrogel facilitated the release of DXMS at the acute inflammatory stage of the early injury and provided effective anti-inflammatory effects for wound sites. Moreover, PLGA composite nanofibers could provide sustained and stable release of DFO for promoting the peritoneal repair by the angiogenesis effects of DFO. The in vivo results indicated that NHP can effectively prevent PIA formation by restraining inflammation and vascularization, promoting peritoneal repair. Therefore, we believe that our NHP has a great potential application in inhibition of PIA.

A Single-Component Janus Zwitterionic Hydrogel Patch with a Bionic Microstructure for Postoperative Adhesion Prevention

The development of anti-adhesion hydrogels for preventing postoperative adhesions is an ongoing challenge, particularly in achieving a balance between exceptional antifouling properties and effective in situ tissue retention. In this study, we propose a unique approach with the design of a single-component Janus zwitterionic hydrogel patch featuring a bionic microstructure. The Janus patches were prepared through free radical polymerization of sulfobetaine methacrylate with N, N'-methylenebis(2-propenamide) as the cross-linker. The incorporation of hexagonal facets separated by interconnecting grooves on one side imparts durable and reliable in situ retention capabilities to the Janus hydrogel patch when it is applied to traumatized tissues. The opposing flat surface exhibits outstanding resistance to bacteria, proteins, and cell adhesion, due to the superhydrophilicity and excellent antifouling characteristics of zwitterionic polymers. This dual functionality empowers the Janus hydrogel patch to mitigate adhesions between traumatized and surrounding tissues. The hexagonal and groove bionic microstructures facilitate rapid drainage, promoting swift contact with the tissue for increased adhesion strength, while independent hexagonal microfacets enhance the peeling energy. In an in vivo setting, Janus zwitterionic hydrogel patches with surface microstructures form mutually embedded structures with the cecum surface, minimizing the likelihood of slippage and detachment. Remarkably, in vivo experiments involving abdominal wall cecum injuries illustrate the Janus zwitterionic hydrogel patch's superior anti-adhesion effectiveness compared to commercial controls. Thus, the Janus hydrogel patch, distinguished by its bionic microstructure surface, presents substantial potential in the biomedical field for averting postoperative adhesions.

Hemoadhican-Based Bioabsorbable Hydrogel for Preventing Postoperative Adhesions

Postoperative peritoneal adhesions are a prevalent clinical issue following abdominal and pelvic surgery, frequently resulting in heightened personal and societal health burdens. Traditional biomedical barriers offer limited benefits because of practical challenges for doctors and their incompatibility with laparoscopic surgery. Hydrogel materials, represented by hyaluronic acid gels, are receiving increasing attention. However, existing antiadhesive gels still have limited effectiveness or carry the risk of complications in clinical applications. Herein, we developed a novel hydrogel using polysaccharide hemoadhican (HD) as the base material and polyethylene glycol diglycidyl ether (PEGDE) as the cross-linking agent. The HD hydrogels exhibit appropriate mechanical properties, injectability, and excellent cytocompatibility. We demonstrate resistance to protein adsorption and L929 fibroblast cell adhesion to the HD hydrogel. The biodegradability and efficacy against peritoneal adhesion are further evaluated in C57BL/6 mice. Our results suggest a potential strategy for anti-postoperative tissue adhesion barrier biomaterials.

Designing a bi-layer multifunctional hydrogel patch based on polyvinyl alcohol, quaternized chitosan and gallic acid for abdominal wall defect repair

In abdominal wall defect repair, surgical site infection (SSI) remains the primary cause of failure, while complications like visceral adhesions present significant challenges following patch implantation. We designed a Janus multifunctional hydrogel patch (JMP) with antibacterial, anti-inflammatory, and anti-adhesive properties. The patch comprises two distinct layers: a pro-healing layer and an anti-adhesion layer. The pro-healing layer was created by a simple mixture of polyvinyl alcohol (PVA), quaternized chitosan (QCS), and gallic acid (GA), crosslinked to form PVA/QCS/GA (PQG) hydrogels through GA's self-assembly effect and hydrogen bonding. Additionally, the PVA anti-adhesive layer was constructed using a drying-assisted salting method, providing a smooth and dense physical barrier to prevent visceral adhesion while offering essential mechanical support to the abdominal wall. The hydrogel patch demonstrates widely adjustable mechanical properties, exceptional biocompatibility, and potent antimicrobial properties, along with a sustained and stable release of antioxidants. In rat models of skin and abdominal wall defects, the JMP effectively promoted tissue healing by controlling infection, inhibiting inflammation, stimulating neovascularization, and successfully preventing the formation of visceral adhesions. These compelling results highlight the JMP's potential to improve the success rate of abdominal wall defect repair and reduce surgical complications.

Biosafe Polydopamine-Decorated MnO2 Nanoparticles with Hemostasis and Antioxidative Properties for Postoperative Adhesion Prevention

Surgical bleeding and cumulative oxidative stress are significant factors in the development of postoperative adhesions, which are always associated with adverse patient outcomes. However, effective strategies for adhesion prevention are currently lacking in clinical practice. In this study, we propose a solution using polydopamine-decorated manganese dioxide nanoparticles (MnO2@PDA) with rapid hemostasis and remarkable antioxidant properties to prevent postsurgical adhesion. The PDA modification provides MnO2@PDA with enhanced tissue adhesiveness and hemocompatibility with negligible hemolysis. Furthermore, MnO2@PDA exhibits impressive antioxidant and free radical scavenging properties, protecting cells from the negative effects of oxidative stress. The hemostatic activity of MnO2@PDA is evaluated in a mouse truncated tail model and a liver injury model, with results demonstrating reduced bleeding time and volume. The in vivo test on a mouse cecal abrasion model shows that MnO2@PDA exhibits excellent antiadhesion properties coupled with alleviated inflammation around the damaged tissue. Therefore, MnO2@PDA, which exhibits high biosafety, rapid hemostasis, and beneficial antioxidant capacity, displays exceptional antiadhesion performance, holding great potential for clinical applications to prevent postoperative adhesion.

Development of melatonin-embedded PLGA-PEG6000 nanofiber biomaterial, and investigation of the effects on abdominal adhesion formation

Abdominal adhesions are still among the most common postsurgical peritoneal inflammation-related complications. Adhesion-related disorders are still highly costly and prevalent due to advances in surgical techniques, treatment methods, and various drugs. The present study aimed to investigate the effects of Poly ( D,L-lactide-co-glycolide) (PLGA)- polyethylene glycol (PEG6000) Nanofiber + Melatonin on the abdominal adhesion model in rats. For this purpose, PLGA-PEG6000 Nanofiber + Melatonin matrix was fabricated and implanted in an experimental abdominal adhesion model in rats. Our study consisted of an in vitro and an in vivo part. The degradation and release profile of the matrix and Melatonin (Mel) embedded matrix was performed in vitro. In vivo, the procedure was carried out with 18 Wistar male rats. Rats were divided into three groups as follows: Sham, Matrix, and Mel + Matrix, respectively. Consequent to degradation and release profiling in vitro, an experimental adhesion model was created and fabricated pure matrix (2 × 2 cm2), and matrix (2 × 2 cm2, 0.25 mg melatonin/per matrix embedded) was applied to injury area in related groups. Intra-abdominal adhesion scores were determined on post-op 21st day, under general anesthesia. Following, cecum, peritoneal tissue, and adhesive bands were harvested. Macroscopic analysis (severity of adhesion formation), Hematoxlyn&Eosin and Masson’s Trichrome staining (for the examination of the levels of infiltration of inflammatory cells, fibrosis, and neovascularization) were performed for the evaluation of the effects of Mel embedded and pure matrix Our results indicated that PLGA-PEG6000 Nanofiber + Melatonin matrix was degraded completely in rats abdominal cavity and significantly reduced adhesion formation compared to other groups macroscopically ( p < 0.05). On the other hand, the histopathological analysis indicated that the fabricated matrix reduced inflammatory cell infiltration, fibrosis, and neovascularization levels.

Techniques for navigating postsurgical adhesions: Insights into mechanisms and future directions

Postsurgical adhesions are a common complication of surgical procedures that can lead to postoperative pain, bowel obstruction, infertility, as well as complications with future procedures. Several agents have been developed to prevent adhesion formation, such as barriers, anti-inflammatory and fibrinolytic agents. The Food and Drug Administration (FDA) has approved the use of physical barrier agents, but they have been associated with conflicting clinical studies and controversy in the clinical utilization of anti-adhesion barriers. In this review, we summarize the human anatomy of the peritoneum, the pathophysiology of adhesion formation, the current prevention agents, as well as the current research progress on adhesion prevention. The early cellular events starting with injured mesothelial cells and incorporating macrophage response have recently been found to be associated with adhesion formation. This may provide the key component for developing future adhesion prevention methods. The current use of physical barriers to separate tissues, such as Seprafilm®, composed of hyaluronic acid and carboxymethylcellulose, can only reduce the risk of adhesion formation at the end stage. Other anti-inflammatory or fibrinolytic agents for preventing adhesions have only been studied within the context of current research models, which is limited by the lack of in-vitro model systems as well as in-depth study of in-vivo models to evaluate the efficiency of anti-adhesion agents. In addition, we explore emerging therapies, such as gene therapy and stem cell-based approaches, that may offer new strategies for preventing adhesion formation. In conclusion, anti-adhesion agents represent a promising approach for reducing the burden of adhesion-related complications in surgical patients. Further research is needed to optimize their use and develop new therapies for this challenging clinical problem.

High-Frequency Bipolar Coagulation Limits Epidural Fibrosis in Lumbar Microdiscectomy

BACKGROUND AND AIM

We propose a vast study to examine the effect of high-frequency bipolar coagulation used in the operating room to prevent the development of epidural fibrosis after lumbar microdiscectomy.

MATERIALS AND METHODS

A total of 1004 participants were divided into two groups: no high-frequency bipolar coagulation (NC group) and high-frequency bipolar coagulation (C group). Postoperative epidural fibrosis, infection rates, reoperation status, and dural injury complications during the operation were recorded.

RESULTS

Considering the epidural fibrosis rates of the two groups, epidural fibrosis was seen in 10.6% of the patients in the NC group. In contrast, it was seen in only 6.2% of the patients in the C group.

CONCLUSION

The complication of epidural fibrosis that develops after lumbar microsurgery operations both impairs patient comfort and brings with it the complications of reoperation. After performing hemostasis with bipolar, coagulating the annulus may effectively reduce epidural fibrosis and prevent reoperation.

Peritoneal Adhesions in Osteopathic Medicine: Theory, Part 1

Peritoneal adhesions form as a result of trauma to the abdomen, injuries resulting from surgery, and infections. These tissutal neoformations are innervated and vascularized, and with lymphatic vessels, adherence becomes a new and independent structure, capable of negatively influencing visceral functions. Adherent neogenesis can be asymptomatic or can be a source of pain, limiting the patient's quality of life. Although adhesiolysis remains the elective approach to eliminate adhesions, this therapeutic route prepares the peritoneal anatomical area to recur. The article reviews information on adhesion formation and peritoneal anatomy, probable subjective predispositions, and pathways that carry nociception. The text aims to be a theoretical basis for making new treatment suggestions for non-invasive osteopathic medicine, through a second part will be discussed in another article.