Current Insight of Collagen Biomatrix for Gingival Recession: An Evidence-Based Systematic Review

Photothermal Modulation of Gingival Fibroblasts via Polydopamine-Coated Zirconia: A Novel Approach for Promoting Peri-Implant Soft Tissue Integration

Achieving robust soft tissue integration around dental implants is crucial for long-term clinical success, as it forms a protective biological seal against bacterial invasion. However, the soft tissue attachment to implants is relatively deficient compared to natural teeth, particularly in the connective tissue region lacking sufficient gingival fibroblasts and perpendicular collagen fiber alignment. This study proposes an innovative strategy to enhance peri-implant soft tissue integration by modulating gingival fibroblast behavior via photothermal conversion. Zirconia surfaces were coated with polydopamine (PDA), a melanin-like polymer exhibiting near-infrared (NIR) absorption for photothermal conversion. Under NIR irradiation, the PDA coating enabled mild hyperthermia (42-43°C) on the zirconia surface through its photothermal effect. Remarkably, this mild photothermal stimulation significantly promoted human gingival fibroblast proliferation, adhesion, and collagen expression compared to unmodified zirconia in vitro. The upregulated collagen production was confirmed at both gene transcription and protein levels. By harnessing the photothermal properties of PDA coatings to modulate cellular behaviors beneficial for connective tissue formation, this pioneering approach provides a promising avenue to achieve improved soft tissue integration and long-term stability of dental implants. The findings highlight the innovative potential of combining biomaterial surface engineering with photothermal therapy concepts for applications in regenerative dentistry.

Comparing the effect of fluoxetine, escitalopram, and sertraline, on the level of BDNF and depression in preclinical and clinical studies: a systematic review

Brain-derived neurotrophic factor (BDNF) dysfunction is one of the most important mechanisms underlying depression. It seems that selective serotonin reuptake inhibitors (SSRIs) improve depression via affecting BDNF level. In this systematic review, for the first time, we aimed to review the effect of three SSRIs including fluoxetine, escitalopram, and sertraline, on both depression and BDNF level in preclinical and clinical studies. PubMed electronic database was searched, and 193 articles were included in this study. After reviewing all manuscripts, only one important difference was found: subjects. We found that SSRIs induce different effects in animals vs. humans. Preclinical studies showed many controversial effects, while human studies showed only two effects: improvement of depression, with or without the improvement of BDNF. However, most studies used chronic SSRIs treatment, while acute SSRIs were not effectively used and evaluated. In conclusion, it seems that SSRIs are reliable antidepressants, and the improvement effect of SSRIs on depression is not dependent to BDNF level (at least in human studies).

The effects of different acetylcholinesterase inhibitors on EEG patterns in patients with Alzheimer's disease: A systematic review

OBJECTIVE

Alzheimer's disease (AD) is a progressive neurodegenerative disorder and the most common type of dementia. The early diagnosis of AD is an important factor for the control of AD progression. Electroencephalography (EEG) can be used for early diagnosis of AD. Acetylcholinesterase inhibitors (AChEIs) are also used for the amelioration of AD symptoms. In this systematic review, we reviewed the effect of different AChEIs including donepezil, rivastigmine, tacrine, physostigmine, and galantamine on EEG patterns in patients with AD.

METHODS

PubMed electronic database was searched and 122 articles were found. After removal of unrelated articles, 24 articles were selected for the present study.

RESULTS

AChEIs can decrease beta, theta, and delta frequency bands in patients with AD. However, conflicting results were found for alpha band. Some studies have shown increased alpha frequency, while others have shown decreased alpha frequency following treatment with AChEIs. The only difference was the type of drug.

CONCLUSIONS

We found that studies reporting the decreased alpha frequency used donepezil and galantamine, while studies reporting the increased alpha frequency used rivastigmine and tacrine. It was suggested that future studies should focus on the effect of different AChEIs on EEG bands, especially alpha frequency in patients with AD, to compare their effects and find the reason for their different influence on EEG patterns. Also, differences between the effects of AChEIs on oligodendrocyte differentiation and myelination may be another important factor. This is the first article investigating the effect of different AChEIs on EEG patterns in patients with AD.

Selection of collagen IV fragments forming the outer sphere of the native protein: Assessment of biological activity for regenerative medicine

The aim of this research was to select the fragments that make up the outer layer of the collagen IV (COL4A6) protein and to assess their potential usefulness for regenerative medicine. It was expected that because protein-protein interactions take place via contact between external domains, the set of peptides forming the outer sphere of collagen IV will determine its interaction with other proteins. Cellulose-immobilized protein fragment libraries treated with polyclonal anti-collagen IV antibodies were used to select the peptides forming the outer sphere of collagen IV. In the first test, 33 peptides that strongly interacted with the polyclonal anti-collagen IV antibodies were selected from a library of non-overlapping fragments of collagen IV. The selected fragments of collagen IV (cleaved from the cellulose matrix) were tested for their cytotoxicity, their effects on cell viability and proliferation, and their impact on the formation of reactive oxygen species (ROS). The studies used RAW 264.7 mouse macrophage cells and Hs 680.Tr human fibroblasts. PrestoBlue, ToxiLight™, and ToxiLight 100% Lysis Control assays were conducted. The viability of fibroblasts cultured with the addition of increasing concentrations of the peptide mix did not show statistically significant differences from the control. Fragments 161-170, 221-230, 721-730, 1331-1340, 1521-1530, and 1661-1670 of COL4A6 were examined for cytotoxicity against BJ normal human foreskin fibroblasts. None of the collagen fragments were found to be cytotoxic. Further research is underway on the potential uses of collagen IV fragments in regenerative medicine.

Advancing Dentistry through Bioprinting: Personalization of Oral Tissues

Despite significant advancements in dental tissue restoration and the use of prostheses for addressing tooth loss, the prevailing clinical approaches remain somewhat inadequate for replicating native dental tissue characteristics. The emergence of three-dimensional (3D) bioprinting offers a promising innovation within the fields of regenerative medicine and tissue engineering. This technology offers notable precision and efficiency, thereby introducing a fresh avenue for tissue regeneration. Unlike the traditional framework encompassing scaffolds, cells, and signaling factors, 3D bioprinting constitutes a contemporary addition to the arsenal of tissue engineering tools. The ongoing shift from conventional dentistry to a more personalized paradigm, principally under the guidance of bioprinting, is poised to exert a significant influence in the foreseeable future. This systematic review undertakes the task of aggregating and analyzing insights related to the application of bioprinting in the context of regenerative dentistry. Adhering to PRISMA guidelines, an exhaustive literature survey spanning the years 2019 to 2023 was performed across prominent databases including PubMed, Scopus, Google Scholar, and ScienceDirect. The landscape of regenerative dentistry has ushered in novel prospects for dentoalveolar treatments and personalized interventions. This review expounds on contemporary accomplishments and avenues for the regeneration of pulp-dentin, bone, periodontal tissues, and gingival tissues. The progressive strides achieved in the realm of bioprinting hold the potential to not only enhance the quality of life but also to catalyze transformative shifts within the domains of medical and dental practices.

Treating Gingival Recessions Using Coronally Advanced Flap or Tunnel Techniques with Autografts or Polymeric Substitutes: A Systematic Review and Meta-Analysis

Gingival recessions are a prevalent oral mucosa alteration. To solve this pathology, palatal mucosa or polymeric soft tissue substitutes are used when performing coronal advanced flap (CAF) or tunnel (TUN) surgical techniques. To evaluate which is the most successful approach, a literature review and meta-analysis were conducted. For the electronic search the National Library of Medicine, the Cochrane Oral Health Group Trials Register, EMBASE and WOS were used. Pooled data for the percentage of root coverage was collected and weighted means were calculated. Heterogeneity was determined using the Higgins (I²) statistic and a random-effects model was applied. Thirteen studies were included in the systematic review (12 randomized and 1 controlled clinical trials) in which both techniques (394 patients) were compared with a follow-up of 4 to 12 months. Galbraith and Baujat plots were used to control for the presence of potential outliers. After performing the meta-analysis (11 studies), the mean root coverage was similar when using the TUN or CAF techniques (p = 0.49). The only differences between the two were found for single recessions, where CAF offered a higher percentage of root coverage (mean difference = 4.98%; p = 0.006). There were no differences when applying an autograft or a polymeric substitute with either of the two tested surgical techniques (p = 0.445).

Probiotics for Alzheimer's Disease: A Systematic Review

Alzheimer’s disease (AD) is the most common form of neurodegenerative disorders affecting mostly the elderly. It is characterized by the presence of Aβ and neurofibrillary tangles (NFT), resulting in cognitive and memory impairment. Research shows that alteration in gut microbial diversity and defects in gut brain axis are linked to AD. Probiotics are known to be one of the best preventative measures against cognitive decline in AD. Numerous in vivo trials and recent clinical trials have proven the effectiveness of selected bacterial strains in slowing down the progression of AD. It is proven that probiotics modulate the inflammatory process, counteract with oxidative stress, and modify gut microbiota. Thus, this review summarizes the current evidence, diversity of bacterial strains, defects of gut brain axis in AD, harmful bacterial for AD, and the mechanism of action of probiotics in preventing AD. A literature search on selected databases such as PubMed, Semantic Scholar, Nature, and Springer link have identified potentially relevant articles to this topic. However, upon consideration of inclusion criteria and the limitation of publication year, only 22 articles have been selected to be further reviewed. The search query includes few sets of keywords as follows. (1) Probiotics OR gut microbiome OR microbes AND (2) Alzheimer OR cognitive OR aging OR dementia AND (3) clinical trial OR in vivo OR animal study. The results evidenced in this study help to clearly illustrate the relationship between probiotic supplementation and AD. Thus, this systematic review will help identify novel therapeutic strategies in the future as probiotics are free from triggering any adverse effects in human body.

A Review of the Effects of Collagen Treatment in Clinical Studies

Collagen, an abundant extracellular matrix protein, has been found to have a lot of pharmaceuticals, medicine, food, and cosmetics applications. Increased knowledge of collagen sources, extraction techniques, structure, and properties in the last decades has helped develop more collagen-based products and tissue engineering biomaterials. Collagen products have been playing an important role in benefiting the health of the human body, especially for aging people. In this paper, the effects of collagen treatment in different clinical studies including skin regeneration, bone defects, sarcopenia, wound healing, dental therapy, gastroesophageal reflux, osteoarthritis, and rheumatoid arthritis have been reviewed. The collagen treatments were significant in these clinical studies. In addition, the associations between these diseases were discussed. The comorbidity of these diseases might be closely related to collagen deficiency, and collagen treatment might be a good choice when a patient has more than one of these diseases, including the coronavirus disease 2019 (COVID-19). It concludes that collagen-based medication is useful in treating comorbid diseases and preventing complications.

Current Insights into Collagen Type I

Collagen type I (Col-I) is unique due to its high biocompatibility in human tissue. Despite its availability from various sources, Col-I naturally mimics the extracellular matrix (ECM) and generally makes up the larger protein component (90%) in vasculature, skin, tendon bone, and other tissue. The acceptable physicochemical properties of native Col-I further enhance the incorporation of Col-I in various fields, including pharmaceutical, cosmeceutical, regenerative medicine, and clinical. This review aims to discuss Col-I, covering the structure, various sources of availability, native collagen synthesis, current extraction methods, physicochemical characteristics, applications in various fields, and biomarkers. The review is intended to provide specific information on Col-I currently available, going back five years. This is expected to provide a helping hand for researchers who are concerned about any development on collagen-based products particularly for therapeutic fields.

Natural-Based Biomaterial for Skin Wound Healing (Gelatin vs. Collagen): Expert Review

Collagen (Col) and gelatin are most extensively used in various fields, particularly in pharmaceuticals and therapeutics. Numerous researchers have proven that they are highly biocompatible to human tissues, exhibit low antigenicity and are easy to degrade. Despite their different sources both Col and gelatin have almost the same effects when it comes to wound healing mechanisms. Considering this, the bioactivity and biological effects of both Col and gelatin have been, and are being, constantly investigated through in vitro and in vivo assays to obtain maximum outcomes in the future. With regard to their proven nutritional values as sources of protein, Col and gelatin products exert various possible biological activities on cells in the extracellular matrix (ECM). In addition, a vast number of novel Col and gelatin applications have been discovered. This review compared Col and gelatin in terms of their structures, sources of derivatives, physicochemical properties, results of in vitro and in vivo studies, their roles in wound healing and the current challenges in wound healing. Thus, this review provides the current insights and the latest discoveries on both Col and gelatin in their wound healing mechanisms.