Efficacy and Safety of PL-5 (Peceleganan) Spray for Wound Infections: A Phase IIb Randomized Clinical Trial.

OBJECTIVE: To assess the safety and efficacy of antimicrobial peptide PL-5 (Peceleganan) spray in the treatment of wound infections. BACKGROUND: Antimicrobial peptide PL-5 spray is a novel topical antimicrobial agent. METHODS: We conducted a multicenter, open-label, randomized, controlled phase IIb clinical trial to evaluate the efficacy and safety of PL-5 spray, as compared with silver sulfadiazine, in patients with skin wound infections. The primary efficacy outcome was the clinical efficacy rate on the first day after ending the treatment (D8). The secondary efficacy outcome was the clinical efficacy rate on the fifth day posttreatment (D5), the bacteria clearance rate, and the overall efficacy rate at the mentioned 2 time points. The safety outcomes included adverse reactions and pharmacokinetic analysis posttreatment. RESULTS: A total of 220 patients from 27 hospitals in China were randomly assigned to 4 groups. On D8, the efficacy rate was 100.0%, 96.7%, 96.7% for the 1‰ PL-5, 2‰ PL-5, 4‰ PL-5 groups, respectively, as compared with 87.5% for the control group. The efficacy rate among the 4 groups was significantly different ( P <0.05). On D5, the efficacy rate was 100.0%, 93.4%, 98.3% for the 1‰ PL-5, 2‰ PL-5, 4‰ PL-5 groups, respectively, as compared with 82.5% for the control group. The efficacy rate among the 4 groups was significantly different ( P <0.05). The blood concentration of PL-5 was not detectable in pharmacokinetic analysis. No severe adverse event related to the application of PL-5 was reported. CONCLUSIONS: Antimicrobial peptide PL-5 spray is safe and effective for the treatment of skin wound infections. TRIAL REGISTRATION: ChiCTR2000033334.

Porcine Acellular Dermal Matrix Increases Fat Survival Rate after Fat Grafting in Nude Mice.

BACKGROUND: Autologous fat grafts have been widely in use for reconstruction, contour abnormalities, and cosmetic surgeries. However, the grafted fat one-year survival rate is unpredictable and always low (20%-80%). Standardizing the existing transplantation technology is difficult due to the limiting conditions. Scaffold materials or drugs are unsuitable to employ because of legal restrictions, complex production, and undetermined hazards. Therefore, a simpler and more effective approach to improve grafted fat survival rate is using commercial products as additives. Earlier studies proved that porcine acellular dermal matrix (PADM), a biomaterial clinically used for wound repair, could work as a scaffold for lipo-implantation. This study aimed at investigating the hitherto unclear effect of PADM on transplanted fat survival. METHODS: Thirty-two 8-week-old female nude mice were divided into two groups. Control mice received a 300 µl fat injection, while the PADM group mice were injected with a 300 µl PADM-fat mixture. After a 4-week treatment, fat weight and liquefaction ratio were assessed. Histological changes were quantified via hematoxylin & eosin (H&E) staining. Macrophage infiltration and vascular regeneration were revealed using an anti-CD34 antibody. Mouse and human mRNA expression levels were gauged via RNA-sequencing. On the third day post implantation, the mRNA expression levels of inflammatory genes Mcp-1 and Tnf-α were measured by qRT-PCR. RESULTS: The weight of surviving grafted fat did not differ between the control and the PADM group. However, adding PADM significantly decreased fat liquefaction. H&E-stained sections showed that PADM decreased fat necrosis, increased fat tissue regeneration, and raised CD34 levels in the regenerated tissue. RNA-sequencing showed that, compared to controls, fats from PADM-added group expressed more mouse-related mRNA but less human-related mRNA. The following GO and KEGG analysis showed that added PADM increased extracellular matrix (ECM) genes expression levels. The qRT-PCR showed that adding PADM increased Mcp-1 and Tnf-α mRNA expression levels. CONCLUSIONS: In summary, PADM addition increased fat survival rate by reducing fat liquefaction through an increased macrophage infiltration, ECM regeneration, and revascularization. Therefore, PADM addition is a workable application in autologous fat grafting. NO LEVEL ASSIGNED: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Peceleganan Spray for the Treatment of Skin Wound Infections: A Randomized Clinical Trial.

Importance: Peceleganan spray is a novel topical antimicrobial agent targeted for the treatment of skin wound infections. However, its efficacy and safety remain unclear. Objective: To assess the safety and efficacy of peceleganan spray for the treatment of wound infections. Design, Setting, and Participants: This multicenter, open-label, phase 3 randomized clinical trial recruited and followed up 570 adult patients diagnosed with secondary open wound infections from 37 hospitals in China from August 23, 2021, to July 16, 2022. Interventions: Patients were randomized to 2 groups with a 2:1 allocation. One group received treatment with 2% peceleganan spray (n = 381) and the other with 1% silver sulfadiazine (SSD) cream (n = 189). Main Outcomes and Measures: The primary efficacy outcome was the clinical efficacy rate (the number of patients fulfilling the criteria for efficacy of the number of patients receiving the treatment) on the first day following the end of treatment (day 8). The secondary outcomes included the clinical efficacy rate on day 5 and the bacterial clearance rate (cases achieving negative bacteria cultures after treatment of all cases with positive bacteria cultures before treatment) on days 5 and 8. The safety outcomes included patients' vital signs, physical examination results, electrocardiographic findings, blood test results, and adverse reactions. Results: Among the 570 patients randomized to 1 of the 2 groups, 375 (98.4%) in the 2% peceleganan treatment group and 183 (96.8%) in the 1% SSD control group completed the trial (n = 558). Of these, 361 (64.7%) were men, and the mean (SD) age was 48.6 (15.3) years. The demographic characteristics were similar between groups. On day 8, clinical efficacy was achieved by 339 patients (90.4%) in the treatment group and 144 (78.7%) in the control group (P < .001). On day 5, clinical efficacy was achieved by 222 patients (59.2%) in the treatment group and 90 (49.2%) in the control group (P = .03). On day 8, bacterial clearance was achieved by 80 of 334 patients (24.0%) in the treatment group and in 75 of 163 (46.0%) in the control group (P < .001). On day 5, bacterial clearance was achieved by 55 of 334 patients (16.5%) in the treatment group and 50 of 163 (30.7%) in the control group (P < .001). The adverse events related to the application of peceleganan spray and SSD cream were similar. Conclusions and Relevance: This randomized clinical trial found that peceleganan spray is a safe topical antimicrobial agent with a satisfactory clinical efficacy rate for the treatment of skin wound infections, while the effectiveness of bacterial clearance remains uncertain. Trial Registration: Chinese Clinical Trial Registry Identifier: ChiCTR2100047202.

Advancements in engineered exosomes for wound repair: current research and future perspectives.

Wound healing is a complex and prolonged process that remains a significant challenge in clinical practice. Exosomes, a type of nanoscale extracellular vesicles naturally secreted by cells, are endowed with numerous advantageous attributes, including superior biocompatibility, minimal toxicity, and non-specific immunogenicity. These properties render them an exceptionally promising candidate for bioengineering applications. Recent advances have illustrated the potential of exosome therapy in promoting tissue repair. To further augment their therapeutic efficacy, the concept of engineered exosomes has been proposed. These are designed and functionally modifiable exosomes that have been tailored on the attributes of natural exosomes. This comprehensive review delineates various strategies for exosome engineering, placing specific emphasis on studies exploring the application of engineered exosomes for precision therapy in wound healing. Furthermore, this review sheds light on strategies for integrating exosomes with biomaterials to enhance delivery effectiveness. The insights presented herein provide novel perspectives and lay a robust foundation for forthcoming research in the realm of cutaneous wound repair therapies.

An experimental model of an electrical injury to the peripheral nerve.

OBJECTIVE: Injury to the peripheral nerves is a common complication found in patients suffering from electrical burns. At present, there are many kinds of experimental models for electrical injury, but no report describes an animal-based experimental model for a relatively simple electrical injury to the peripheral nerves. We have designed and constructed a specific device to generate increasingly severe electrical shocks of a known voltage for the experiment. This device can simulate injuries of different degrees (minor, medium and severe) caused by shock to the right sciatic nerve of rats. METHOD: Thirty Sprague-Dawley rats were randomly divided into Group I (3600 V, n=10), Group II (1000 V, n=10) and Group III (500 V, n=10). The voltage required for the electrical shock was generated by the above-mentioned device and was adjusted to deliver 3600, 1000 and 500 V, respectively. The specific voltage, as mentioned above, was delivered three times to the right sciatic nerve of the rats. The shock duration was set to last for 10 ms. The time interval between the shocks was 3 min. Three rats were randomly selected from each group to observe changes in the morphology, electric physiology of the nerve and their histology the first, second and fourth week after injury. RESULTS: All rats survived the injuries. Leg function was partially impaired and swellings occurred on the injured extremity. However, by the second week after the injury the rats had recovered. Digit ulcers were observed by the fourth week after injury in Groups I and II. Neural electric physiology showed that the recovery rate of the neural conduction velocity (RNCV) disappeared in part or in whole immediately after the injury in experimental rats. RNCV recovered up to 65% in Group III and to 7% in Group II by the fourth week after injury, however, RNCV did not recover in Group I at all. Histology showed that blood vessel embolism occurred within the injured nerve. A large number of nerve fibres experienced Waller degeneration while the myelin sheath was vacuolated. The neural plate disintegrated largely by the first week after injury and the myelin sheath disintegrated into a loose structure by the second week after injury in Group I. Group II displayed a similar situation as Group I, wherein some nerve fibres experienced Waller degeneration and disintegration. Regenerative myelin appeared in some rats at about the fourth week after injury. The following changes were seen in Group III: The degree of neural injuries was different. The point of entry of the electric currents showed obvious Waller degeneration and disintegration of the myelin sheath, while some nerves showed a regenerated myelin sheath by the second week after injury. The morphology (such as quantity and diameter) of the injured myelin was basically normal by the fourth week after injury. CONCLUSION: This device can produce controlled injuries to the sciatic nerve giving different degrees of severity (minor, medium and severe), by means of varying the electrical shock voltage and shock duration on the rats. It is a useful model for experimental studies of injuries to peripheral nerves.

Collagen/chitosan based two-compartment and bi-functional dermal scaffolds for skin regeneration.

Inspired from the sophisticated bilayer structures of natural dermis, here, we reported collagen/chitosan based two-compartment and bi-functional dermal scaffolds. Two functions refer to mediating rapid angiogenesis based on recombinant human vascular endothelial growth factor (rhVEGF) and antibacterial from gentamicin, which were encapsulated in PLGA microspheres. The gentamicin and rhVEGF encapsulated PLGA microspheres were further combined with collagen/chitosan mixtures in low (lower layer) and high (upper layer) concentrations, and molded to generate the two-compartment and bi-functional scaffolds. Based on morphology and pore structure analyses, it was found that the scaffold has a distinct double layered porous and connective structure with PLGA microspheres encapsulated. Statistical analysis indicated that the pores in the upper layer and in the lower layer have great variations in diameter, indicative of a two-compartment structure. The release profiles of gentamicin and rhVEGF exceeded 28 and 49 days, respectively. In vitro culture of mouse fibroblasts showed that the scaffold can facilitate cell adhesion and proliferation. Moreover, the scaffold can obviously inhibit proliferation of Staphylococcus aureus and Serratia marcescens, exhibiting its unique antibacterial effect. The two-compartment and bi-functional dermal scaffolds can be a promising candidate for skin regeneration.

Evaluation of optimized continuous venovenous hemodiafiltration therapy efficiency in severe burn patients with sepsis.

As an initial factor, sepsis and multiple organ dysfunction syndrome (MODS) caused by sepsis are the principal causes of death in burned patients. In this report, we measured the levels of tumor necrosis factor (TNF)-α, interleukin (IL)-6 and IL-8 in severely burned patients with sepsis after the initiation of continuous vein-vein hemodiafiltration (CVVHDF) to evaluate the clinical usefulness of CVVHDF on the removal of key mediators. The vital sign indices, such as the heart rate (HR), respiration (R) and central venous pressure (CVP), were recorded at 0 and 42 h in each group. Further, the laboratory examinations indexes, such as the white blood cell count, blood sugar, serum sodium, blood urea nitrogen and serum creatinine, were detected in venous blood samples. Twenty-two severely burned patients suffering from sepsis were randomized into the control group (A, n = 11) and the experimental group (B, n = 11). The patients in group A underwent conventional treatment, and those in group B received conventional+CVVHDF treatment. The vital signs, such as the HR, R, and CVP, and laboratory examination indices, such as the blood cell count, blood sugar, serum sodium, blood urea nitrogen, and serum creatinine, dropped significantly in group B compared with those in group A at 42 h (P < 0.05). The plasma levels of TNF-α, IL-6 and IL-8 were measured at 0, 12, 18, 24, 36 and 42 h after the start of CVVHDF and at the same time points after the patients were diagnosed with sepsis in group A. The plasma levels of TNF-α in group B decreased by 32% at 18 h after the start of CVVHDF and decreased by 43% at 42 h after the start of CVVHDF; however, these levels were increased compared with the normal values (P < 0.01). The plasma levels of IL-6 decreased at 18 h after the start of CVVHDF (0.274 ± 0.137 ng/ml). Following a brief increase at 24 h, the plasma levels of IL-6 again decreased continuously until the end of the investigation (0.192 ± 0.119 ng/ml). The plasma levels of IL-8 in group B decreased by 56% at 18 h after the start of CVVHDF, but they were increased compared with the normal values (P < 0.01). The plasma levels of IL-8 in group B decreased by 70% at 42 h after the start of CVVHDF, but they were increased compared with the normal values (P < 0.01). The MODS incident was 4 of 11 in group A compared with 1 of 11 in group B (P < 0.01). In conclusion, CVVHDF can effectively reduce the levels of TNF-α, IL-6 and IL-8 as well as the MODS incidence in patients with serious burns.

[Isolation, culture and cryopreservation of cells derived from fetal appendages].

OBJECTIVE: To investigate the optimal method for isolation, culture and cryopreservation of cells from fetal appendages, for the purpose of providing viable cells for tissue engineering, cell therapy and gene therapy. METHODS: Trypsin dispersion method was used to isolate cells from human umbilical cord and placenta. The tissues from umbilical cord and placenta were cryopreserved with dimethylsulfoxide (DMSO) in different concentrations. Then the percentage of living cells in thawed tissues, and their micro-structure were observed and compared with fresh tissues under transmission electron microscope. The expression of cell immune phenotype before and after cryopreservation were detected with immuno-histochemistry method. RESULTS: The percentage of living cells in human fresh umbilical cord was 67.0%, while that in cryopreserved umbilical cord was 23.4%, 55.5%, 48.8%, 31.8%, respectively in 5%, 10%, 15%, 20% of DMSO. The percentage of living cells in cryopreserved tissues was similar to that of fresh tissues when the volume percentage of DMSO was 10% (P > 0.05), and it was significantly different with that when volume percentage of DMSO was 5% and 20% (P < 0.01). The result by transmission electron microscope was coincident with the results shown above. The results were similar between placenta and umbilical cord. There was no obvious changes in immune phenotype of the tissue and cells after cryopreservation. CONCLUSION: Cryopreservation with this method can isolate a large amount of cells from fetal appendages, with no changes in immune phenotype after cryopreservation, and the effect was best when the volume percentage of DMSO was 10%.

[Changes in the calcitonin content after inhalation injury in dogs].

OBJECTIVE: To investigate the changes in the serum content of immunoreactive calcitonin (iCT) after burns or inhalation injury, and to explore its diagnostic significance. METHODS: Twenty-four dogs were randomized into 4 groups, i. e. A (n = 6, with moderate degree inhalation injury) , B ( n = 6, with severe inhalation injury), C (n = 6, with most severe inhalation injury) and D (n = 6, with severe burns) groups. The serum content of iCT and blood gas analysis before and after injury were determined at different time points. The degree of inhalation injury was determined with fibrobronchoscopic examination at 6 post-inhalation injury hour (PIH). RESULTS: (1) Fiber bronchoscopic examination showed that the degree of inhalation injury in each group was coincident with the anticipation. (2) The serum content of iCT in each group at 1 PIH was obviously higher than that before injury, and it was evidently higher in A, B and C groups than that in D group at 4 PIH. The peak value of iCT in group A at 24 PIH was (453+/-224) ng/L, and it increased gradually in B and C groups at 48 PIH. The serum content of iCT increased continually from 2 PIH on, and it reached (125+/-41) ng/L at 48 PIH. (3) Compared with PaO2 value before injury (109+/-8) mmHg, there was no obvious difference of the PaO, in A and D groups. PaO2 value in B and C group began to descend continually at 8 PIH (65+/-6) mmHg, and that in C group began to descend at 4 PIH (71+/-9) mmHg. PaCO2 value in C group began to increase at 24 PIH(52+/-11) mmHg when compared with that before injury(38+/-5 ) mmHg. CONCLUSION: The changes in the serum level of iCT within 8 PIH occurred much earlier than PaO2 and PaCO2, thus it has the same diagnostic significance as fibers bronchoscopic examination.

[Respiratory support with high frequency jet ventilation in severely burned patients with inhalation injury during early postburn stage].

OBJECTIVE: To observe the effects of respiratory support with high frequency jet ventilation (HFJV) in severely burned patients with inhalation injury during early postburn stage. METHODS: Twenty severely burned patients with TBSA of 79.6 +/- 29.3% and inhalation injury were enrolled in the study. Nineteen cases received tracheostomy after admission and only one received nasal intubation. All the patients underwent HFJV to correct hypoxia. The changes in blood gas analysis, respiratory rate and pulse were recorded before and 11 days after the ventilation. RESULTS: Tracheostomy was performed on 2.7 +/- 2.4 postburn days (PBDs), and HFJV was given during 4.4 +/- 2.9 PBDs. PaO(2) was evidently higher during 1 - 3 days after HFJV than that before the ventilation (P < 0.01) and remained at high level for 1 week after HFJV. There was no change in PaCO(2), respiratory rate and pulse during the ventilation. CONCLUSION: HFJV was beneficial in improving oxygenation and without any obvious side effects during the early management of severely burned patients with inhalation injury. This might be an optimal respiratory support pattern.