Modified host defence peptide GF19 slows TNT-mediated spread of corneal herpes simplex virus serotype I infection.

Corneal HSV-1 infections are a leading cause of infectious blindness globally by triggering tissue damage due to the intense inflammation. HSV-1 infections are treated mainly with antiviral drugs that clear the infections but are inefficient as prophylactics. The body produces innate cationic host defence peptides (cHDP), such as the cathelicidin LL37. Various epithelia, including the corneal epithelium, express LL37. cHDPs can cause disintegration of pathogen membranes, stimulate chemokine production, and attract immune cells. Here, we selected GF17, a peptide containing the LL37 fragment with bioactivity but with minimal cytotoxicity, and added two cell-penetrating amino acids to enhance its activity. The resulting GF19 was relatively cell-friendly, inducing only partial activation of antigen presenting immune cells in vitro. We showed that HSV-1 spreads by tunneling nanotubes in cultured human corneal epithelial cells. GF19 given before infection was able to block infection, most likely by blocking viral entry. When cells were sequentially  exposed to viruses and GF19,  the infection was attenuated but not arrested, supporting the contention that the GF19 mode of action was to block viral entry. Encapsulation into silica nanoparticles allowed a more sustained release of GF19, enhancing its activity. GF19 is most likely suitable as a prevention rather than a virucidal treatment.

Combinatorial Effect of Biomaterials and Extracellular Vesicle Therapy for Heart Failure with Reduced Ejection Fraction: A Systematic Review of Preclinical Studies.

Heart failure, a pervasive global health burden, necessitates innovative therapeutic strategies. Extracellular vesicles (EVs) have emerged as promising contenders for cardiac repair, owing to their profound influence on fibrosis and inflammation. Merging EVs with biomaterials holds the potential for a synergistic leap in therapeutic efficacy. In this review, the impact of combining EVs with biomaterials in preclinical heart failure models is scrutinized. Fifteen studies, predominantly employing mesenchymal stromal cell-derived EVs along with hyaluronic acid or peptides in coronary ligation models, meet these stringent criteria. The amalgamation of EVs and biomaterials consistently enhances cardiac ejection fraction (1.39; 95% CI: 0.68, 2.11; p = 0.0001) and fractional shortening (1.46, 95% CI: 0.70, 2.22; p = 0.0002) compared to EV monotherapy. Secondary outcomes similarly showcased improvement in the combined treatment group. Although the number of studies analyzed is modest, no indications of publication bias surface. In summary, combination therapy with EVs and biomaterials enhances therapeutic benefit in preclinical heart failure models. The consistent improvement observed across diverse EV sources, biomaterials, and animal models underscores the exciting potential of this synergistic approach.

Phosphorylcholine and KR12-Containing Corneal Implants in HSV-1-Infected Rabbit Corneas.

Severe HSV-1 infection can cause blindness due to tissue damage from severe inflammation. Due to the high risk of graft failure in HSV-1-infected individuals, cornea transplantation to restore vision is often contraindicated. We tested the capacity for cell-free biosynthetic implants made from recombinant human collagen type III and 2-methacryloyloxyethyl phosphorylcholine (RHCIII-MPC) to suppress inflammation and promote tissue regeneration in the damaged corneas. To block viral reactivation, we incorporated silica dioxide nanoparticles releasing KR12, the small bioactive core fragment of LL37, an innate cationic host defense peptide produced by corneal cells. KR12 is more reactive and smaller than LL37, so more KR12 molecules can be incorporated into nanoparticles for delivery. Unlike LL37, which was cytotoxic, KR12 was cell-friendly and showed little cytotoxicity at doses that blocked HSV-1 activity in vitro, instead enabling rapid wound closure in cultures of human epithelial cells. Composite implants released KR12 for up to 3 weeks in vitro. The implant was also tested in vivo on HSV-1-infected rabbit corneas where it was grafted by anterior lamellar keratoplasty. Adding KR12 to RHCIII-MPC did not reduce HSV-1 viral loads or the inflammation resulting in neovascularization. Nevertheless, the composite implants reduced viral spread sufficiently to allow stable corneal epithelium, stroma, and nerve regeneration over a 6-month observation period.

In situ Tissue Regeneration in the Cornea from Bench to Bedside.

Corneal blindness accounts for 5.1% of visual deficiency and is the fourth leading cause of blindness globally. An additional 1.5-2 million people develop corneal blindness each year, including many children born with or who later develop corneal infections. Over 90% of corneal blind people globally live in low- and middle-income regions (LMIRs), where corneal ulcers are approximately 10-fold higher compared to high-income countries. While corneal transplantation is an effective option for patients in high-income countries, there is a considerable global shortage of corneal graft tissue and limited corneal transplant programs in many LMIRs. In situ tissue regeneration aims to restore diseases or damaged tissues by inducing organ regeneration. This can be achieved in the cornea using biomaterials based on extracellular matrix (ECM) components like collagen, hyaluronic acid, and silk. Solid corneal implants based on recombinant human collagen type III were successfully implanted into patients resulting in regeneration of the corneal epithelium, stroma, and sub-basal nerve plexus. As ECM crosslinking and manufacturing methods improve, the focus of biomaterial development has shifted to injectable, in situ gelling formulations. Collagen, collagen-mimetic, and gelatin-based in situ gelling formulas have shown the ability to repair corneal wounds, surgical incisions, and perforations in in-vivo models. Biomaterial approaches may not be sufficient to treat inflammatory conditions, so other cell-free therapies such as treatment with tolerogenic exosomes and extracellular vesicles may improve treatment outcomes. Overall, many of the technologies described here show promise as future medical devices or combination products with cell or drug-based therapies. In situ tissue regeneration, particularly with liquid formulas, offers the ability to triage and treat corneal injuries and disease with a single regenerative solution, providing alternatives to organ transplantation and improving patient outcomes.

Design, characterization, and evaluation of antibacterial gels, Boc-D-Phe-γ4-L-Phe-PEA/chitosan and Boc-L-Phe-γ4-L-Phe-PEA/chitosan, for biomaterial-related infections.

Self-assembled peptide gels have generated interest as antibacterial materials to prevent biomaterial-related infections but these peptides are often associated with poor proteolytic stability. Efforts have been made to stabilize peptides by incorporating non-natural amino acids and/or linkages but complexation with polymers have not been explored. Therefore, we developed self-assembled peptide/chitosan gels, Boc-D-Phe-γ4-L-Phe-PEA (NH007)/chitosan and Boc-L-Phe-γ4-L-Phe-PEA (NH009)/chitosan, by complexing dipeptide NH007 or NH009 with chitosan in DMSO:acetic acid. The gels were characterized using SEM, FTIR, contact angle, and rheology data and found to exhibit excellent viscoelastic and self-healing characteristics. Complexation with chitosan led to an increase in stability against proteolytic degradation. Peptide/chitosan gels showed broad spectrum antibacterial activities against Gram-negative and Gram-positive bacteria, such as Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Bacillus subtilis at a high inoculum of 107-108 cfu/mL. NH007/chitosan gels showed 70-75% inhibition, whereas NH009/chitosan showed 78-81% inhibition and NH009/chitosan gels, in particular, showed strong antibacterial activity against pathogenic strain of P. aeruginosa. A unique feature of these gels is that the antibacterial activities did not decrease gradually but were sustained for up to 48 h. The mechanistic studies using SEM and HR-TEM indicated interaction of gels with bacterial membrane components, leading to cell lysis. The MTT and LDH assays indicated >90% cell viability and only 8-10% toxicity towards NIH 3T3 fibroblast cells. Thus, peptide/chitosan gels developed in the present work showed improved proteolytic stability and sustained antibacterial activities and, therefore, may be used for preventing biomaterial-related infections.

Maxillofacial Nursing: Assessing the Knowledge and Awareness of Nurses in Handling Maxillofacial Injuries Through a Comprehensive Survey.

AIM: To assess the knowledge and awareness of nurses in handling maxillofacial injuries. METHOD: A cross-sectional questionnaire study was conducted among the staff nurses of the multi-specialty Gokul Newtech Hospital, Jamnagar, Gujarat. Forty nursing staff were included in the study. Kruskal-Wallis ANOVA, Spearman's correlation and Mann-Whitney U tests were applied for statistical analysis. RESULT: There was no statistically significant difference between the mean knowledge score concerning the study participant's age, work experience, and education. According to the survey, a majority of the nurses either did not know the answer or answered incorrectly. CONCLUSION: It can be concluded that there is a requirement of new guidelines and recommendations in the existing teaching and training modules being followed by the nursing schools across the country.

Broad-Spectrum Antibacterial Activity of Proteolytically Stable Self-Assembled αγ-Hybrid Peptide Gels.

Bacterial infections pose a serious threat to mankind, and there is immense interest in the design and development of self-assembled peptide gels using ultrashort peptides for antibacterial applications. The peptide gels containing natural amino acids suffer from poor stability against proteolytic enzymes. Therefore, there is a need to design and develop peptide gels with improved stability against proteolytic enzymes. In the present work, we report the synthesis and characterization of α/γ hybrid peptides Boc-D-Phe-γ4-L-Phe-PEA (NH007) and Boc-L-Phe-γ4-L-Phe-PEA (NH009) to improve the proteolytic stability. Both of the dipeptides were found to self-assemble into gels in aqueous DMSO (3-5% w/v), and the self-assembly process was studied using FTIR and CD, which indicated antiparallel ß-sheet formation with random coils in NH007 gels and random or unordered conformation in NH009. The rheological studies indicated viscoelastic characteristics for both gels; the storage modulus ( G') for NH007 and NH009 gels (3% w/v) was estimated as 0.2 and 0.5 MPa, higher than the loss modulus ( G''). Also, both gels demonstrated self-healing characteristics for six consecutive cycles when subjected to varying strains of 0.1 and 30% (200 s each). The peptide gels were incubated with a mocktail of proteolytic enzymes, proteinase K, pepsin, and chymotrypsin, and stability was monitored using RP HPLC. Up to 23 and 40% degradation was observed for NH007 (3%, w/v) in 24 and 36 h, and 77 and 94% degradation was observed for NH009 (3%, w/v), within the same period. Thus α/γ hybrid peptide gels containing D-Phe exhibited higher stability than gels fabricated using L-Phe. The use of D-residue in α/γ hybrid peptide significantly enhanced the stability of peptides against proteolytic enzymes, as the stability data reported in this work are possibly the best in class. Both peptide gels exhibited broad-spectrum antibacterial activity against Gram-negative and Gram-positive bacteria, such as Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis, and Staphylococcus aureus. The Pseudomonas aeruginosa and Staphylococcus aureus, in particular, are known to develop resistance. The NH007 (3%, w/v) demonstrated 65% inhibition, whereas NH009 (3%, w/v) showed 78% inhibition, with potent activity against Pseudomonas aeruginosa. Mechanistic studies, using SEM, HR-TEM, and bacterial live-dead assay, indicated entrapment of bacteria in gel networks, followed by interaction with cell membrane components and lysis. Cell viability (MTT assay) and toxicity (LDH assay) studies showed that both gels are not toxic to NIH 3T3 mouse embryonic fibroblast cells (mammalian). MTT assay showed >85% cell viability, and LDH assay exhibited not more than 15% cytotoxicity, even at higher concentrations (5%, w/v) and prolonged exposures (48 h). Overall, studies indicate the potential application of gels developed from the α/γ hybrid peptides in preventing biomaterial-related infections.

Versatility of Titanium 3D Plate in Comparison with Conventional Titanium Miniplate Fixation for the Management of Mandibular Fracture.

BACKGROUND: In the present study, 20 patients with mandibular fracture were included to evaluate the versatility of titanium 3D plate in comparison with conventional titanium miniplate fixation. METHODS: The patients were alternatively allocated to either the 3D plate group or Miniplate group. The patients were evaluated for the clinical assessment of mobility after fixation, pre and post-surgical occlusal relationship, adequacy of reduction on post operative radiograph and any post surgical complications. RESULTS: All 25 fractures in 20 patients were found to be adequately fixed when checked intra-operatively. No post-operative IMF was required in either of the groups. The mean radiographic score at post operative time interval in Miniplate group was found to be 2.80 ± 0.42 and in 3D Plate was found to be 2.90 ± 0.32. The mean radiographic score at 3 months time interval in Miniplate group was found to be 2.70 ± 0.48 and in 3D Plate was found to be 2.70 ± 0.48. Radiolucency at 3 months period was found in 1 patient (10%) in the miniplate group and it was not found in any patients in the 3D plate group. None of the patients in both the groups had complications of non-union or mal-union. In miniplate group, 2 patients (20%) had infections and in 3D plate group 1 patient (10%) had infection. 3 patients in miniplate group had occlusal discrepancies (30%) and 1 patient in 3D plate group had occlusal discrepancies (10%). Overall, complications were found in 6 patients (60%) in miniplate group and 2 patients (20%) in 3D plate group. The data when compared was statistically significant (P < 0.05). CONCLUSION: The 3D plating system was found to be advantageous over conventional miniplates. It uses lesser foreign material, reduces the operation time and overall cost of the treatment. Thus 3D plate can be used as an alternative to conventional miniplates. The system is reliable and effective treatment modality for mandibular fractures.