Effects of basic fibroblast growth factor-2 and hyaluronic acid on tracheal wound healing

Therapeutic Strategies and Genetic Implications for Periodontal Disease Management: A Systematic Review

The objective of this review is to identify the microbiological alterations caused by various therapy modalities by critically analyzing the current findings. We limited our search to English-language papers published between 1 January 2004 and 7 May 2024 in PubMed, Scopus, and Web of Science that were relevant to our topic. In the search approach, the Boolean keywords "microbio*" AND "periodontitis" were used. A total of 5152 papers were obtained from the databases Web of Science (2205), PubMed (1793), and Scopus (1154). This resulted in 3266 articles after eliminating duplicates (1886), and 1411 entries were eliminated after their titles and abstracts were examined. The qualitative analysis of the 22 final articles is included in this study. Research on periodontal disease shows that periodontitis alters the oral microbiome and increases antibiotic resistance. Treatments like scaling and root planing (SRP), especially when combined with minocycline, improve clinical outcomes by reducing harmful bacteria. Comprehensive mechanical debridement with antibiotics, probiotics, EMD with bone grafts, and other adjunctive therapies enhances periodontal health. Personalized treatment strategies and advanced microbial analyses are crucial for effective periodontal management and antibiotic resistance control.

Controlled processivity in glycosyltransferases: A way to expand the enzymatic toolbox

Glycosyltransferases (GT) catalyse the biosynthesis of complex carbohydrates which are the most abundant group of molecules in nature. They are involved in several key mechanisms such as cell signalling, biofilm formation, host immune system invasion or cell structure and this in both prokaryotic and eukaryotic cells. As a result, research towards complete enzyme mechanisms is valuable to understand and elucidate specific structure-function relationships in this group of molecules. In a next step this knowledge could be used in GT protein engineering, not only for rational drug design but also for multiple biotechnological production processes, such as the biosynthesis of hyaluronan, cellooligosaccharides or chitooligosaccharides. Generation of these poly- and/or oligosaccharides is possible due to a common feature of several of these GTs: processivity. Enzymatic processivity has the ability to hold on to the growing polymer chain and some of these GTs can even control the number of glycosyl transfers. In a first part, recent advances in understanding the mechanism of various processive enzymes are discussed. To this end, an overview is given of possible engineering strategies for the purpose of new industrial and fundamental applications. In the second part of this review, we focused on specific chain length-controlling mechanisms, i.e., key residues or conserved regions, and this for both eukaryotic and prokaryotic enzymes.

Efficacy of stem cell secretome loaded in hyaluronate sponge for topical treatment of psoriasis

Psoriasis vulgaris is an inflammatory disease characterized by distinctive skin lesions and dysregulated angiogenesis. Recent research uses stem cell secretion products (CM); a set of bioactive factors with therapeutic properties that regulate several cellular processes, including tissue repair and angiogenesis. The aim of this work was to evaluate the effect of CM of Wharton's gelatin MSC (hWJCM) in a treatment based on the bioactivation of a hyaluronic acid matrix (HA hWJCM) in a psoriasiform-like dermatitis (PD) mouse model. A preclinical study was conducted on PD mice. The effect of hWJCM, Clobetasol (Clob) gold standard, HA Ctrl, and HA hWJCM was tested topically evaluating severity of PD, mice weight as well as skin, liver, and spleen appearance. Treatment with either hWJCM, HA Ctrl or HA hWJCM, resulted in significant improvement of the PD phenotype. Moreover, treatment with HA hWJCM reduced the Psoriasis Area Severity Index (PASI), aberrant angiogenesis, and discomfort associated with the disease, leading to total recovery of body weight. We suggest that the topical application of HA hWJCM can be an effective noninvasive therapeutic solution for psoriasis, in addition to other skin diseases, laying the groundwork for future studies in human patients.

Characterization and biological evaluation of a novel silver nanoparticle-loaded collagen-chitosan dressing

Effective coverage and protection is a priority in wound treatment. Collagen and chitosan have been widely used for wound dressings due to their excellent biological activity and biocompatibility. Silver nanoparticles (AgNPs) have a powerful antibacterial effect. In this study, a macromolecular and small-molecular collagen mixed solution, a macromolecular and small-molecular chitosan mixed solution were prepared, and a silver nanoparticle-loaded collagen-chitosan dressing (AgNP-CCD) has been proposed. First, the effects of a collagen-chitosan mixed solution on the proliferation of human umbilical vein endothelial cells and the secretion of cytokines were evaluated. Then, the characteristics and antibacterial effects of the AgNP-CCD were tested, and the effects on wound healing and the influence of wound cytokine expression were investigated via a deep second-degree burn wound model. The results showed that at the proper proportion and concentration, the collagen-chitosan mixed solution effectively promoted cell proliferation and regulated the levels of growth factors (vascular endothelial growth factor [VEGF], epidermal growth factor [EGF], platelet-derived growth factor [PDGF], transforming growth factor [TGF-β1], basic fibroblastic growth factor [bFGF]) and inflammatory factors (TNF-α, IL-1β, IL-6, IL-8). Moreover, AgNP solutions at lower concentrations exerted limited inhibitory effects on cell proliferation and had no effect on cytokine secretion. The AgNP-CCD demonstrated satisfactory morphological and physical properties as well as efficient antibacterial activities. An in vivo evaluation indicated that AgNP-CCD could accelerate the healing process of deep second-degree burn wounds and played an important role in the regulation of growth and inflammatory factors, including VEGF, EGFL-7, TGF-β1, bFGF, TNF-α and IL-1β. This AgNP-CCD exerted excellent biological effects on wound healing promotion and cytokine expression regulation.

Biosynthesis of Hyaluronic acid polymer: Dissecting the role of sub structural elements of hyaluronan synthase

Hyaluronic acid (HA) based biomaterials have several biomedical applications. HA biosynthesis is catalysed by hyaluronan synthase (HAS). The unavailability of 3-D structure of HAS and gaps in molecular understanding of HA biosynthesis process pose challenges in rational engineering of HAS to control HA molecular weight and titer. Using in-silico approaches integrated with mutation studies, we define a dictionary of sub-structural elements (SSE) of the Class I Streptococcal HAS (SeHAS) to guide rational engineering. Our study identifies 9 SSE in HAS and elucidates their role in substrate and polymer binding and polymer biosynthesis. Molecular modelling and docking assessment indicate a single binding site for two UDP-substrates implying conformationally-driven alternating substrate specificities for this class of enzymes. This is the first report hypothesizing the involvement of sites from SSE5 in polymer binding. Mutation at these sites influence HA production, indicating a tight coupling of polymer binding and synthase functions. Mutation studies show dispensable role of Lys-139 in substrate binding and a key role of Gln-248 and Thr-283 in HA biosynthesis. Based on the functional architecture in SeHAS, we propose a plausible three-step polymer extension model from its reducing end. Together, these results open new avenues for rational engineering of Class I HAS to study and regulate its functional properties and enhanced understanding of glycosyltransferases and processive enzymes.

Potential for Respiratory Epithelium Regeneration from Induced Pluripotent Stem Cells

Objectives:

In cases of laryngeal inflammatory lesions and tracheal invasion of a malignant tumor, autologous tissue implantation techniques using skin or cartilage are often applied. However, these techniques are both invasive and unstable. The purpose of this study was to evaluate the potential use of induced pluripotent stem (iPS) cells in the regeneration of respiratory epithelium.

Methods:

We seeded iPS cells on low-attachment plates in serum-free media to generate embryoid bodies (EBs). After a 3-day culture, the EBs were transferred to a gelatin-coated dish supplemented with activin A alone or with basic fibroblast growth factor (induction groups). As a control, EBs were cultured without these growth factors (control group). Cultured tissues from all groups were histologically examined for 2 weeks.

Results:

In the induction groups, the presence of respiratory epithelium-like tissue was observed with hematoxylin and eosin staining after 14 days of culture.

Conclusions:

This study demonstrated the potential use of iPS cells in regeneration of the respiratory epithelium.

Regeneration of tracheal epithelium using a collagen vitrigel-sponge scaffold containing basic fibroblast growth factor

OBJECTIVES

Our group has had good results in tracheal mucosal regeneration using a collagen vitrigel-sponge scaffold in an animal model. In this study, the effectiveness of this scaffold with the application of basic fibroblast growth factor (b-FGF) was investigated.

METHODS

A collagen vitrigel-sponge scaffold was fabricated with simultaneous addition of b-FGF. Three types of collagen vitrigel-sponge scaffolds were made: no b-FGF, 10 ng of b-FGF, and 100 ng of b-FGF. At 3, 5, 7, and 14 days after implantation in rats, the tracheas were removed and histologically evaluated. The regeneration of mucosal epithelium and the subepithelial layer was evaluated.

RESULTS

Mucosal epithelium, including pseudostratified epithelium and ciliated cells, regenerated earlier in the scaffolds when b-FGF was applied than when b-FGF was not applied. Regeneration of the subepithelial layer, infiltration of inflammatory cells and fibroblasts, and angiogenesis were promoted earlier in the scaffolds with b-FGF application.

CONCLUSIONS

Our technique for tracheal reconstruction using collagen vitrigel-sponge scaffolds with b-FGF application affords a feasible approach for accelerating the regeneration of the intraluminal surface and subepithelial layer of tracheal tissue.

[Influence of Aloe polysaccharide on proliferation and hyaluronic acid and hydroxyproline secretion of human fibroblasts in vitro]

OBJECTIVE

To investigate the effect of Aloe polysaccharide on proliferation and hyaluronic acid and hydroxyproline secretion of human fibroblasts in vitro.

METHODS

The fibroblasts were treated with different doses of polysaccharide (0, 25, 50, 100, 200, 400 mg/L). Subsequently, cell proliferation was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, cell cycle by flow cytometry, evaluation of the Aloe polysaccharide toxic effect by acridine orange-ethidium bromide staining, evaluation of the cell injury by lactate dehydrogenase (LDH) assay, and the collagen synthesis by (3)H-proline incorporation. In addition, hyaluronic acid and hydroxyproline levels in the supernatants of cultured fibroblasts were measured by enzyme-linked immunosorbent assay.

RESULTS

The proliferation of fibroblasts was induced with polysaccharide in a dose-dependent manner, reaching its highest level on 5th day. Meanwhile, the percentage of cells at phase G(0)/G(1) was decreased, while that at phases G(2)/M and S was increased significantly in Aloe polysaccharide-treated groups as compared with those in the control group (P<0.05). Additionally, the apoptosis of the fibroblasts showed no differences among all groups. The collagen synthesis was increased and cell injury decreased in polysaccharide-treated groups as compared with those in control group (P<0.05), while the levels of hyaluronic acid and hydroxyproline in the supernatants of fibroblasts treated with polysaccharide were significantly higher than those in the control group (P<0.05).

CONCLUSION

The Aloe polysaccharide promotes both the proliferation of fibroblasts and the production of hyaluronic acid and hydroxyproline in fibroblasts. This indicates that the Aloe polysaccharide may play an important role in the extracellular matrix remodeling during wound healing.

A tissue-engineering approach for stenosis of the trachea and/or cricoid

CONCLUSION

This new regenerative therapy shows great potential for the treatment of stenosis of the trachea and/or cricoids (STC).

OBJECTIVES

To estimate the potential of tissue-engineered artificial trachea (AT) for treatment of STC in clinical applications. We previously reported that AT was a useful material for implantation into a tracheal defect after resection of cancer. There are many causes of stenosis of the respiratory tract and STC is particularly difficult to treat.

METHODS

The AT was a spiral stent composed of Marlex mesh made of polypropylene and covered with collagen sponge made from porcine skin. Three patients with STC were treated by this tissue-engineering method. All of them suffered from STC caused by long endotracheal intubations. They underwent a two-stage operation. In the first operation, after resection of the stenotic regions, the edge of the tracheal cartilage was sutured to the edge of the skin. The tracheal lumen was exposed and a T-shaped cannula was inserted into the large tracheostoma. At 3 weeks to 2 months after the first operation, the trachea and skin were separated. The trimmed AT with venous blood and basic fibroblast growth factor (b-FGF) was then implanted into the cartilage defect.

RESULTS

Postoperatively, all patients were able to breathe easily and had no discomfort in their daily activities. Six months after the second operation, we observed enough air space in the trachea and cricoid by computed tomography (CT) imaging and fiber endoscopy.