Increased Collagen Density Research Articles

Uterine scars after caesarean delivery: From histology to the molecular and ultrastructural level.

Uterine rupture during a trial of labor after caesarean delivery (CD) is a serious complication for mother and fetus. The lack of knowledge on histological features and molecular pathways of uterine wound healing has hindered research in this area from evolving over time. We analysed collagen content and turnover in uterine scars on a histological, molecular and ultrastructural level. Therefore, tissue samples from the lower uterine segment were obtained during CD from 16 pregnant women with at least one previous CD, from 16 pregnant women without previous CD, and from 16 non-pregnant premenopausal women after hysterectomy for a benign disease. Histomorphometrical collagen quantification showed, that the collagen content of the scar area in uterine wall specimens after previous CD was significantly higher than in the unscarred myometrium of the same women and the control groups. Quantitative real-time PCR of uterine scar tissue from FFPE samples delineated by laser microdissection yielded a significantly higher COL3A1 expression and a significantly lower COL1A2/COL3A1 ratio in scarred uteri than in samples from unscarred uteri. Histological collagen content and the expression of COL1A2 and COL3A1 were positively correlated, while COL1A2/COL3A1 ratio was negatively correlated with the histological collagen content. Transmission electron microscopy revealed a destroyed myometrial ultrastructure in uterine scars with increased collagen density. We conclude that the high collagen content in uterine scars results from an ongoing overexpression of collagen I and III. This is a proof of concept to enable further analyses of specific factors that mediate uterine wound healing.

Fisetin, a potential skin rejuvenation drug that eliminates senescent cells in the dermis.

Accumulation of senescent fibroblasts, chronic inflammation, and collagen remodeling due to aging-related secretory phenotypes have been hypothesized to cause age-related skin aging, which results in wrinkles and loss of skin elasticity, thus compromising appearance attractiveness. However, the rejuvenating effects of removing senescent cells from the human skin and the efficacy of related therapeutic agents remain unclear. Here, we investigated the effects of fisetin, a potential anti-aging component found in various edible fruits and vegetables, on senescent human dermal fibroblasts (HDFs) and aging human skin. Senescence was induced in primary HDFs using long-term passaging and treatment with ionizing radiation, and cell viability was assessed after treatment with fisetin and a control component. A mouse/human chimeric model was established by subcutaneously transplanting whole skin grafts from aged individuals into nude mice, which were treated intraperitoneally with fisetin or control a component for 30 d. Skin samples were obtained and subjected to senescence-associated-beta-galactosidase staining; the extent of aging was evaluated using western blotting, reverse transcription-quantitative PCR, and histological analysis. Fisetin selectively eliminated senescent dermal fibroblasts in both senescence-induced cellular models; this effect is attributable to cell death induction by caspases 3, 8, and 9-mediated endogenous and exogenous apoptosis. Fisetin-treated senescent human skin grafts showed increased collagen density and decreased senescence-associated secretory phenotypes (SASP), including matrix metalloproteinases and interleukins. No apparent adverse events were observed. Thus, fisetin could improve skin aging through selective removal of senescent dermal fibroblasts and SASP inhibition, indicating its potential as an effective novel therapeutic agent for combating skin aging.

Transdermal Sustained Release Properties and Anti-Photoaging Efficacy of Liposome-Thermosensitive Hydrogel System.

Drug delivery systems have become a research priority in the biomedical field. The incorporation of liposomes to hydrogels further forms more robust multifunctional systems for more effective and sustained topical drug delivery. In this study, carboxymethyl-modified chitosan/hyaluronic acid (CMC/HA, CMH) thermosensitive hydrogel is developed for sustained transdermal delivery of liposomes. Hydrogels are crosslinked by hydrogen bonding, hydrophobic interaction and electrostatic interaction. The gel properties can be regulated by substitution degree (DS), and when DS = 18.20 ± 0.67% (CMH2), the gel temperature is 37.8°C, allowing rapid gelation at body temperature (315 s). Moreover, CMH2 hydrogel has suitable spreadability (17.7-57.2cm2 ), viscosity (2133.4mPas) and porous structure, which facilitated its adhesion and application on the skin and liposomes delivery. The hydrogel can retard the liposomesrelease, and the release rate of ascorbyl glucoside (AA2G)is 33.92-49.35% in 24h. Hydrogel avoids the rapid clearance of liposomes from the skin and improved the skin retention, achieving the long-term release of bioactive components. Liposome-hydrogel system more efficiently promotes the anti-photoaging effect of AA2G on skin, reducing epidermal thickness, melanin deposition and lipid oxidative damage and increasing collagen density. Therefore, liposome-hydrogel systems are proposed as multifunctional delivery systems for sustained transdermal delivery.

Organization of collagen fibers and tissue hardening: Markers of fibrotic scarring after spinal cord injury in mice revealed by multiphoton-atomic force microscopy imaging

Spinal cord injury is a dramatic disease leading to severe motor, sensitive and autonomic impairments. After injury the axonal regeneration is partly inhibited by the glial scar, acting as a physical and chemical barrier. The scarring process involves microglia, astrocytes and extracellular matrix components, such as collagen, constructing the fibrotic component of the scar. To investigate the role of collagen, we used a multimodal label-free imaging approach combining multiphoton and atomic force microscopy. The second harmonic generation signal exhibited by fibrillar collagen enabled to specifically monitor it as a biomarker of the lesion. An increase in collagen density and the formation of more tortuous fibers over time after injury are observed. Nano-mechanical investigations revealed a noticeable hardening of the injured area, correlated with collagen fibers' formation. These observations indicate the concomitance of important structural and mechanical modifications during the fibrotic scar evolution.

Administration of Arabica Coffee Bean (Coffea Arabica) Cream Extract from Wamena Papua Can Reduce MMP-1 And Increase Collagen in Wistar Male Rats (Rattus Norvegicus) Exposed to Ultraviolet-B

Introduction: The aim of the study was to determine the effectiveness of Arabica coffee bean extract cream (Coffea arabica) from Wamena in reducing MMP-1 levels and increasing collagen density in Wistar rats (Rattus norvegicus) exposed to UV-B light. Methods: This is a post-test only control group design experimental study using male rats as subjects. Each group was exposed to UV light and smeared with coffee bean cream extract from Wamena every day. Then the back skin tissue was taken and the amount of collagen was examined by Picro Sirius Red staining and MMP1 levels were examined by ELISA staining. Results: The mean MMP-1 levels in groups P1, P2, and P3 respectively 7.57 ± 0.70, 5.99 ± 0.60, and 4.57 ± 0.36. The average percentage of collagen in the P1, P2, and P3 groups was 72.23 ± 4.42, 77.80 ± 2.73, and 81.05 ± 2.77, respectively. The average MMP-1 level decreased with the increasing dose of Wamena arabica coffee bean extract cream. The mean percentage of collagen increased with increasing doses of Wamena arabica coffee bean extract cream in experimental animals. Conclusion: Administration of 3% and 6% Wamena Arabica coffee bean extract cream can inhibit the increase in MMP-1 levels and can increase the amount of collagen in male wistar rats (Rattus norvegicus) exposed to UV-B light. Keywords: Arabica coffee bean, MMP-1, Collagen

Collagen-nanoclay hydrogels for stiffness enhancement of the extracellular matrix: the effect on spheroid growth

The extracellular matrix (ECM) is crucial for regulating cellular functions and maintaining tissue integrity. Alterations in ECM stiffness are associated with various pathological conditions, including cancer and cardiovascular disease. Therefore, being able to tailor and customize ECM stiffness could revolutionize personalized research and therapies in tissue engineering. Clay nanomaterials are an emerging class of biomaterials with unique properties that make them promising candidates for biomedical applications.
 In this study, we investigated the potential of laponite nanoclays (LapNC) to enhance the mechanical properties of collagen hydrogels without increasing the collagen amount. Collagen hydrogels of different concentrations (2.5, 4, and 6 mg/ml) were supplemented with LapNC, and the resulting hydrogels were thoroughly characterized using rheology, scanning electron microscopy (SEM) and other assays to quantify additional physical parameters, such as the permeability and swelling potential. In this study, we investigated the potential application of the customized hydrogels as 3D cancer culture systems for tumor spheroid growth. To this end, we quantified the spheroid area over time by culturing three cancer cell lines in the supplemented and non-supplemented matrices. Moreover, we assessed the migration capacity of the spheroids with respect to the initial cluster formation.
 Our results confirmed that LapNC solution could be successfully incorporated into the culture media without clay aggregation. The supplemented hydrogels exhibited enhanced mechanical properties without compromising cellular viability or causing collagen collapse. Regardless of the collagen concentration, LapNC-supplemented hydrogels showed higher storage moduli and lower permeability than control hydrogels, which was qualitatively corroborated by SEM visualization of the porosity. Furthermore, the addition of LapNC resulted in the formation of larger spheroids at every collagen concentration. These findings have significant implications for tissue engineering applications, particularly in cancer spheroid analysis.
 The successful incorporation of LapNC into collagen hydrogels as nanofillers to modify the rheological and structural properties highlights their potential for tissue engineering applications. Our results demonstrate that the mechanical properties of collagen hydrogels can be enhanced by the addition of LapNC without increasing collagen density. This may provide a powerful method for personalized research and therapies in multiple fields of tissue engineering. In particular, our study suggests that LapNC-supplemented hydrogels can serve as 3D cancer culture systems for stiffness-dependent tumor spheroid growth, opening up new avenues for cancer research and therapy.

Bioprosthetic Valve Deterioration: Accumulation of Circulating Proteins and Macrophages in the Valve Interstitium

Histologic evaluations revealed excessive accumulations of macrophages and absence of fibroblastic interstitial cells in explanted bioprosthetic valves. Comprehensive gene and protein expression analysis and histology unveiled an accumulation of fibrinogen and plasminogen, an activator of infiltrated macrophages, from degenerated valve surfaces in the interstitial spaces. These pathologies were completely reproduced in a goat model replaced with an autologous pericardium-derived aortic valve. Further preclinical animal experiments using goats demonstrated that preventing infiltration of macrophages and circulating proteins by increasing collagen density and leaflet strength is an effective treatment option.

Navitoclax (ABT-263) rejuvenates human skin by eliminating senescent dermal fibroblasts in a mouse/human chimeric model.

Chronic senescence, such as aging, contributes to age-related tissue dysfunction and disease development. The accumulation of senescent fibroblasts and the senescence-associated secretory phenotype are particularly implicated in this process. Removal of senescent cells has been reported to prevent tissue dysfunction and extend life span during aging. ABT-263 (navitoclax), which inhibits antiapoptotic proteins, is a leading antiaging drug; however, its role in human skin aging is unclear. This study aimed to determine the rejuvenating effects of ABT-263 on aging skin using a human skin graft mouse model. We assessed the viability of ABT-263-treated skin fibroblasts after inducing senescence. Aged human skin was transplanted under the back skin of nude mice and injected intraperitoneally with the drug or control. Analysis of the skin specimens revealed that ABT-263 induced selective elimination of senescent dermal fibroblasts. Senescent human skin treated with ABT-263 exhibited a decrease in the number of senescent cells and in the expression of aging-related secretory phenotype molecules, such as matrix metalloproteinases and interleukins and an increase in collagen density. Our results indicate that selective removal of senescent skin cells with ABT-263 can improve the aging phenotype of human skin without side effects. ABT-263 is, thus, a novel potential therapeutic agent for skin aging.

The Effect of Chayote (Sechium Edule) Extract Cream Can Reduce Matrix Metalloproteinase-2 (MMP-2) Levels and Increase Collagen Density in The Wound Healing Process of Male Wistar Rats (Rattus Novergicus) With Diabetes Mellitus

Introduction: The main complication in Diabetes Mellitus patients is delayed wound healing resulting in chronic wounds. Chayote is known as a vegetable, which has anti-inflammatory properties. The tannin and saponin compounds in chayote produce antibacterial agents. This study aims to prove the role of chayote extract cream on the wound healing process of diabetic rats through MMP-2 markers and collagen density. Methods: This study was an experimental post-test only control group design using male rats. Samples were induced hyperglycaemia with 46 mg of nicotinamide and 10 mg of streptozotocin one week before the experiment. The sample was divided into 2 groups: the placebo group (P0) and the treatment group (P1) with a total of 11 samples per group. The treatment group received cream of chayote extract 60% for 1 week. On the 8th day, both groups were taken by punch biopsy to assess collagen density, then examined for MMP-2 levels in the blood. Results: The average MMP-2 level in the control group was 4.97 ± 0.36 ng/ml, while the average MMP-2 in the treatment group was 4.59 ± 0.42 ng/ml. The average collagen level in the control group was 37.08 ± 12.92 %/ body surface, while the mean collagen in the treatment group was 54.21 ± 15.76 %/ body surface. Conclusion: Administration of ethanol extract of chayote (Sechium edule) significantly reduced matrix metalloproteinase-2 (MMP-2) levels and increased collagen density in the wound healing process of rats.

Hyaluronic Acid Dissolving Microneedles and Nonablative Fractional Laser for Infraorbital Wrinkles: A Prospective, Randomized, Split‐Face Study

Background. Recently, hyaluronic acid dissolving microneedles (HA‐DMNs) have been widely used in antiwrinkle research studies. However, the comparison of HA‐DMNs with nonablative fractional laser (NAFL), which is regarded as the gold standard in the treatment of facial wrinkles, is still lacking. Objective. The purpose was to compare the therapeutic effects and adverse effects of HA‐DMNs and NAFL on infraorbital wrinkles. Methods. A prospective, randomized, split‐face trial was performed with HA‐DMNs on one side and NAFL on the other. The wrinkle numbers, photo‐numeric scores, and VISIA assessment scores were compared at baseline and 2, 4, 8, and 12 weeks post‐treatment. Reflectance confocal microscopy (RCM) was used to monitor collagen fibers. Adverse effects and subjects’ satisfaction scores were evaluated using scales. Results. The final analysis included 28 patients. The wrinkle numbers and photo‐numeric scores decreased on both the HA‐DMNs side and the NAFL side in week‐2, 4, 8, and 12. The VISIA scores decreased on the HA‐DMNs side in week‐8 and on the NAFL side in week‐2. There were no significant differences in these indexes between the two sides. The RCM images demonstrated a similar increase in collagen density on the two sides. Burning, erythema, edema, and crust scores were higher on the NAFL side than on the HA‐DMNs side. There was no significant difference in the subjects’ satisfaction scores of the two sides. Conclusion. HA‐DMNs are effective treatment options for infraorbital rejuvenation. From the change of wrinkle numbers and scores, HA‐DMNs provided comparable efficacy as NAFL in an observation period of 12 weeks. Meanwhile, HA‐DMNs offered a more favorable adverse effect profile than NAFL therapy. Mild but persistent pain, erythema, and edema during the HA‐DMNs therapy are noteworthy and require improvement.

The Effect of Acemannan Hydrogel on Collagen Expression in Gingival Tissue of Diabetes Mellitus Animal Model

Background: Diabetes mellitus is a comorbid disease that greatly interferes with the process of wound healing, including injuries to the gingival tissue. The Aloe vera plant, or Aloe vera, is one of Indonesia's natural wealth, which is often found and has been widely used by the community in overcoming various health problems, including to treat various wounds. This study aims to explore the potential of hydrogen acemannan to repair gingival tissue in rats with diabetes mellitus.
 Methods: An in vivo experimental study using 24 Wistar rats grouped into 4 groups (negative control, 25%, 50%, and 75% acemannan hydrogel). Collagen density was assessed histologically semiquantitatively. Data analysis was performed using SPSS using univariate, bivariate, and multivariate methods.
 Results: The administration of acemannan hydrogel showed an increase in the collagen density score along with an increase in the concentration of acemannan hydrogel. Administration of 25%, 50%, and 75% acemannan hydrogel showed significant differences in the collagen density score compared to the group that did not receive acemannan hydrogel treatment, p<0.05.
 Conclusion: Acemannan hydrogel application can increase collagen density in gingival tissue of diabetes mellitus animal model.

Glutaminase inhibitors rejuvenate human skin via clearance of senescent cells: a study using a mouse/human chimeric model.

Skin aging caused by various endogenous and exogenous factors results in structural and functional changes to skin components. However, the role of senescent cells in skin aging has not been clarified. To elucidate the function of senescent cells in skin aging, we evaluated the effects of the glutaminase inhibitor BPTES (bis-2-(5-phenylacetamido-1, 3, 4-thiadiazol-2-yl)ethyl sulfide) on human senescent dermal fibroblasts and aged human skin. Here, primary human dermal fibroblasts (HDFs) were induced to senescence by long-term passaging, ionizing radiation, and treatment with doxorubicin, an anticancer drug. Cell viability of HDFs was assessed after BPTES treatment. A mouse/human chimeric model was created by subcutaneously transplanting whole skin grafts from aged humans into nude mice. The model was treated intraperitoneally with BPTES or vehicle for 30 days. Skin samples were collected and subjected to reverse transcription-quantitative polymerase chain reaction (RT-qPCR), western blotting, and histological analysis. BPTES selectively eliminated senescent dermal fibroblasts regardless of the method used to induce senescence; aged human skin grafts treated with BPTES exhibited increased collagen density, increased cell proliferation in the dermis, and decreased aging-related secretory phenotypes, such as matrix metalloprotease and interleukin. These effects were maintained in the grafts 1 month after termination of the treatment. In conclusion, selective removal of senescent dermal fibroblasts can improve the skin aging phenotype, indicating that BPTES may be an effective novel therapeutic agent for skin aging.

MR Imaging and Electrophysiological Features of Doxorubicin-Induced Fibrosis: Protocol Development in a Small Preclinical Pig Study with Histological Validation

A critical chemotherapeutic complication is cardiotoxicity, often leading, in time, to heart failure. In this work, we developed a novel animal protocol using magnetic resonance (MR) imaging and electrophysiology (EP) tests, designed to detect subtle structural and functional changes associated with myocardial damage in sub-chronic phases post-chemotherapy. A weekly dose of doxorubicin (DOX) was injected in four juvenile swine throughout a four-week plan, using an intravenous approach that mimics the treatment in cancer patients. We performed cardiac MR imaging as follows: in all four pigs pre-DOX; at 1 and 5 weeks post-DOX in a group of two pigs; and, at 1 and 9 weeks post-DOX in the other two pigs, using Cine imaging to assess ejection fraction (EF) and late gadolinium enhancement to quantify collagen density in the left ventricle. Additionally, X-ray-guided voltage mapping and arrhythmia tests were conducted in the group at 9 weeks post-DOX and in a healthy pig. Tissue samples were collected for histology. The results showed that EF decreased from ~46% pre-DOX to ~34% within the first 9 weeks post-DOX. This decline in LV function was explained by a gradual increase in collagen density, especially noticeable at week 9 post-DOX as derived from MRI analysis. Furthermore, ventricular fibrillation was induced via rapid pacing at 9 weeks post-DOX, most likely caused by fibrotic patches identified in voltage maps, as confirmed by MRI and collagen-sensitive histological stains. Overall, our novel preclinical protocol was able to reveal key signs of potentially-irreversible tissue changes, along with electrical remodeling and arrhythmia risk in the early months following DOX therapy. Future work will include more datasets to statistically power the study, and will use the protocol to test cardioprotective strategies.

3D Collagen Fiber Concentration Regulates Treg Cell Infiltration in Triple Negative Breast Cancer.

BackgroundTriple negative breast cancer (TNBC) is characterized by poor prognosis and a lack of effective therapeutic agents owing to the absence of biomarkers. A high abundance of tumor-infiltrating regulatory T cells (Tregs) was associated with worse prognosis in malignant disease. Exploring the association between Treg cell infiltration and TNBC will provide new insights for understanding TNBC immunosuppression and may pave the way for developing novel immune-based treatments.Materials and MethodsPatients from TCGA were divided into Treg-high (Treg-H) and Treg-low (Treg-L) groups based on the abundance of Tregs according to CIBERSORT analysis. The association between expression level of Tregs and the clinical characteristics as well as prognosis of breast cancer were evaluated. Next, a Treg-related prognostic model was established after survival-dependent univariate Cox and LASSO regression analysis, companied with an external GEO cohort validation. Then, GO, KEGG and GSEA analyses were performed between the Treg-H and Treg-L groups. Masson and Sirius red/Fast Green staining were applied for ECM characterization. Accordingly, Jurkat T cells were encapsulated in 3D collagen to mimic the ECM microenvironment, and the expression levels of CD4, FOXP3 and CD25 were quantified according to immunofluorescence staining.ResultsThe expression level of Tregs is significantly associated with the clinical characteristics of breast cancer patients, and a high level of Treg cell expression indicates a poor prognosis in TNBC. To further evaluate this, a Treg-related prognostic model was established that accurately predicted outcomes in both TCGA training and GEO validation cohorts of TNBC patients. Subsequently, ECM-associated signaling pathways were identified between the Treg-H and Treg-L groups, indicating the role of ECM in Treg infiltration. Since we found increasing collagen concentrations in TNBC patients with distant migration, we encapsulated Jurkat T cells within a 3D matrix with different collagen concentrations and observed that increasing collagen concentrations promoted the expression of Treg biomarkers, supporting the regulatory role of ECM in Treg infiltration.ConclusionOur results support the association between Treg expression and breast cancer progression as well as prognosis in the TNBC subtype. Moreover, increasing collagen density may promote Treg infiltration, and thus induce an immunosuppressed TME.

The Effect of Ethanolic Extract from Moringa oleifera Leaves in Collagen Density and Numbers of New Capillary Vessel Count on Wistar Rats Burn Wound

Background: Burns are a major cause of morbidity, including prolonged length of stay and disability, which requires no small amount of treatment costs. Currently, there are many studies to accelerate the healing of wounds, one of which is with Moringa oleifera (MO). This study aimed to prove the effect of ethanolic extract from MO leaves on collagen density and new capillary vessel count on Wistar rats' burn wounds.
 Methods: This research is randomized post-test only with a control group design. Twenty-four male Wistar rats induced burn wounds and were randomly divided into 4 groups which were given topical medicine once daily for 10 days; P1 (MO leaves extract 10%), P2 (Silver Sulfadiazine + MO leaves extract 10%), P3 (SSD), and P4 (negative control). Collagen density was assessed using the Kruskal-Wallis test and continued with Mann-Whitney Test. New capillary vessel count was assessed using Hematoxylin-Eosin staining and One Way ANOVA. The correlation test between two variables was tested using the Spearman test.
 Results: Collagen Density shows significant difference in group P1 compared to P4 (p=0,016), group P2 compared to P3 (p=0,047), group P2 compared to P4 (p=0,009). A significant increase in new capillary blood vessel counts was seen in group P1 compared to P3 and P4 (p=0.001; 0,000) and group P2 compared to P3 and P4 (p=0,000;0,000). A positive correlation was found between the new capillary blood vessel count and epithelization percentage (p=0,001), with a strong correlation (rho=0,682).
 Conclusion: Ethanolic extract from Moringa oleifera leaves proved to be effective in increasing collagen density and new capillary vessel count.

Attenuation of intrinsic ageing of the skin via elimination of senescent dermal fibroblasts with senolytic drugs.

Skin ageing is caused by numerous factors that result in structural and functional changes in cutaneous components. Research has shown that senescent cells are known to accumulate in skin ageing, however, the role of senescent cells in skin ageing has not been defined. To elucidate the role of the senescent cell in skin ageing, we evaluated the effect of known senolytic drugs on senescent dermal fibroblasts. Primary human dermal fibroblasts (HDFs) were induced to senescence by long-term passaging, UV irradiation, and H2 O2 treatment. Cell viability was measured after treatment of ABT-263 and ABT-737 on HDFs. Young and aged hairless mice were intradermally injected with drugs or vehicle on the dorsal skin for 10 days. Skin specimens were obtained and reverse-transcription quantitative PCR, western blotting, and histological analysis were performed. We found that ABT-263 and ABT-737 induced selective clearance of senescent dermal fibroblasts, regardless of the method of senescence induction. Aged mouse skin treated with ABT-263 or ABT-737 showed increased collagen density, epidermal thickness, and proliferation of keratinocytes, as well as decreased senescence-associated secretory phenotypes, such as MMP-1 and IL-6. Taken together, our results indicate that selective clearance of senescent skin cells can attenuate and improve skin ageing phenotypes and that senolytic drugs may be of potential use as new therapeutic agents for treating ageing of the skin.

Effect of Blue-Light-Emitting Diode Exposure on Collagen Density of Periodontal Ligament During Orthodontic Tooth Movement in Rats

Photobiomodulation therapy using Light Emitting Diode (LED) with a certain period and intensity can stimulate tissue repair and accelerate orthodontic tooth movement. During remodeling, collagen on periodontal ligaments was formed on the pressure and tension sides. The aim of this study was to investigate the effect of exposure time and observation day of blue LED on the collagen density of periodontal ligament of the pressure and tension sides of Wistar rats. Forty-eight male Wistar rats aged 3-4 months weighing 300-500 grams were divided into four groups: the control group; the group exposed to LED with λ1000 nm of 490 mW/cm2 for 25, 30, and 35 seconds once a day. In addition, their mandibular inter-incisor was administered with thirty-five grams orthodontic force using an open coil spring. The calculations on the collagen density of pressure and tension sides were carried out on days 0, 3, 7, and 14 using the TinEye application. Statistical analysis test was conducted using two-way ANOVA and LSD post hoc test. The results showed a more significant increase in the collagen density of the pressure and tension sides than that of the control group (p <0.05). The collagen density of pressure and tension sides reach the highest point at 30 seconds exposure followed by 35 and 25 seconds. The collagen density of pressure sides decreased on the 3rd day and increased afterward, and the tension sides continued to increase on the 3rd day afterward. The study showed that blue light LEDs were able to increase collagen density on the pressure and tension sides, with optimal exposure at 30 seconds, and it reached the highest point at day 14.

Topical retinoic acid induces corneal strengthening by upregulating transglutaminase 2 in murine cornea

Transglutaminase 2 (TG2) is the most abundant crosslinking enzyme in murine and human cornea, while retinoids are well-known inducers of TG2 expression. This study aims to determine if the retinoic acid supplementation can increase corneal stiffness by crosslinking through upregulating the corneal TG2 expression. The right eyes of C57BL/6 mice were treated with 2 × 10−2M retinol palmitate (VApal) eyedrops or control eyedrops and hold for 30 min, once a day for 28 consecutive days. The WB and qPCR results showed increased expression of TG2 in murine cornea with the prolongation of VApal eyedrop application. After 28 days of VApal eyedrop treatment, the increased TG2 were found catalytically active and distributed in corneal epithelium and stroma as detected by 5-(biotinamido) pentylamine (5-BP) incorporation method and immunofluorescence staining. The transmission electron microscope image revealed that VApal treated cornea manifested with increased collagen density in anterior and middle layer of stroma. The higher elastic module was found among VApal treated cornea by nano-indentation test. In cultured corneal epithelial cells and keratocytes, all-trans retinoid acid (ATRA) treatment increased the content of TG2 in cell lysis and in culture medium. These results indicate that retinoic acid induce the reinforcement of the cornea by TG2 mediated crosslinking via increasing the TG2 expression in corneal epithelium and keratocyte. As TG2 was found to be less in the cornea of keratoconus patients in several RNA-sequencing studies, retinoic acid could serve as a non-invasive prevention method for keratoconus progression.

GEL EKSTRAK RIMPANG JAHE MERAH MENINGKATKAN KEPADATAN KOLAGEN PASCA EKSTRAKSI GIGI MARMUT

Introduction: tooth extraction can cause injury involving the bone structure and soft tissue of the oral cavity. Tooth extraction can cause various complications, one of which is bleeding. Red ginger is a type of spice that is most widely used in various food and beverage recipes. Red ginger is commonly used by the public as a cold, digestive, antipyretic, anti-inflammatory, and analgesic drug. Various studies have shown that ginger has antioxidant properties, flavonoids, and oleoresins found in the rhizome. The purpose of this study was to determine the effect of the concentration of red ginger extract (Zingiber Officinale Varr. Rubrum) on collagen density after extraction of guinea pig teeth (Cavia porcellus). Materials and method: the method of this research is an experimental in vivo laboratory with a post-test-only control group design. The hypothesis test was carried out by the One Way Anova test and was carried out on 24 male guinea pigs. The experimental animals were divided into 4 groups which were distinguished by concentration, 10%, 20%, 30%, and the control group given 2% CMC-Na gel respectively. Results and discussions: The results showed that red ginger extract gel concentrations of 10%, 20%, and 30% can increase collagen density compared to CMC-Na 2%. Conclusion: the red ginger extract gel with a concentration of 30% was most effective at increasing collagen density compared to concentrations of 10% and 20%.

Salep Ekstrak Daun Kersen Meningkatkan Kepadatan Kolagen dan Mempercepat Penyembuhan Luka Sayat pada Kulit Mencit Hiperglikemia

This study aims to determine the effect of Muntingia calabura‘s leaves extract ointment on the healing of cuts in the skin of hyperglycemic mice in terms of collagen density. This study used 24 male mice (Mus musculus) with alloxan induced hyperglycemia (150 mg/kg body weight) intraperitoneal. Skin incisions are made on the back using a scalpel with a length of ± 15 mm and a depth reaching the subcutaneous. The experimental animals were randomly divided into four treatments and each treatment consisted of six replications, namely the control was given a placebo, and the treatment of cherry leaf extract ointment with a concentration of 30%, 40%, and 50%. The process of wound healing was observed histopathological with collagen density parameters. Based on the results, there was an increase in collagen density in each treatment. The mean collagen density in treatment (T) 0% (T0) 0.60; at treatment 30% (T1) 0.73; at treatment 40% (T3) 1,46; at 50% treatment (T3) was 2.20. The results of the study through the Kruskal Wallis test stated that the cherry leaf extract ointment had a very significant effect on the healing of the incision wound of hyperglycemic mice as seen from the density of collagen. We conclude that the administration of 50% cherry leaf extract ointment is the most effective in accelerating the healing of the hyperlycemic mice incision wounds in terms of collagen density.