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Kawai M.Y., Ozasa R., Ishimoto T., et al. Periodontal Tissue as a Biomaterial for Hard-Tissue Regeneration following bmp-2 Gene Transfer. Materials, 15, 3, 993. https://doi.org/10.3390/ma15030993., The application of periodontal tissue in regenerative medicine has gained increasing interest since it has a high potential to induce hard-tissue regeneration, and is easy to handle and graft to other areas of the oral cavity or tissues. Additionally, bone morphogenetic protein-2 (BMP-2) has a high potential to induce the differentiation of mesenchymal stem cells into osteogenic cells. We previously developed a system for a gene transfer to the periodontal tissues in animal models. In this study, we aimed to reveal the potential and efficiency of periodontal tissue as a biomaterial for hard-tissue regeneration following a bmp-2 gene transfer. A non-viral expression vector carrying bmp-2 was injected into the palate of the periodontal tissues of Wistar rats, followed by electroporation. The periodontal tissues were analyzed through bone morphometric analyses, including mineral apposition rate (MAR) determination and collagen micro-arrangement, which is a bone quality parameter, before and after a gene transfer. The MAR was significantly higher 3–6 d after the gene transfer than that before the gene transfer. Collagen orientation was normally maintained even after the bmp-2 gene transfer, suggesting that the bmp-2 gene transfer has no adverse effects on bone quality. Our results suggest that periodontal tissue electroporated with bmp-2 could be a novel biomaterial candidate for hard-tissue regeneration therapy.

Kawai M.Y., Ozasa R., Ishimoto T., et al. Periodontal Tissue as a Biomaterial for Hard-Tissue Regeneration following bmp-2 Gene Transfer. Materials, 15, 3, 993. https://doi.org/10.3390/ma15030993., The application of periodontal tissue in regenerative medicine has gained increasing interest since it has a high potential to induce hard-tissue regeneration, and is easy to handle and graft to other areas of the oral cavity or tissues. Additionally, bone morphogenetic protein-2 (BMP-2) has a high potential to induce the differentiation of mesenchymal stem cells into osteogenic cells. We previously developed a system for a gene transfer to the periodontal tissues in animal models. In this study, we aimed to reveal the potential and efficiency of periodontal tissue as a biomaterial for hard-tissue regeneration following a bmp-2 gene transfer. A non-viral expression vector carrying bmp-2 was injected into the palate of the periodontal tissues of Wistar rats, followed by electroporation. The periodontal tissues were analyzed through bone morphometric analyses, including mineral apposition rate (MAR) determination and collagen micro-arrangement, which is a bone quality parameter, before and after a gene transfer. The MAR was significantly higher 3–6 d after the gene transfer than that before the gene transfer. Collagen orientation was normally maintained even after the bmp-2 gene transfer, suggesting that the bmp-2 gene transfer has no adverse effects on bone quality. Our results suggest that periodontal tissue electroporated with bmp-2 could be a novel biomaterial candidate for hard-tissue regeneration therapy.

Guided tissue regeneration (GTR) involves the prevention of epithelial down growth in gingival connective tissue by utilizing a barrier membrane, which favors the regeneration of periodontal tissues. This study aims to produce chitosan (Chi)-coated polycaprolactone (PCL) GTR membranes that can prevent inflammation by providing local release of antibiotic/anti-inflammatory drug metronidazole (MET), and can eliminate the need of second periodontal surgery via degradation. PCL fibers (20%) containing 5 and 15 wt.% of MET were fabricated with electrospinning, and then subsequently coated with Chi solutions (5%) for the first time in literature to obtain enhanced fiber biodegradability. Increasing drug concentration caused a decrease in PCL solution viscosity, which resulted in thinner fibers as demonstrated by SEM images. The incorporation of drug as well as the post Chi coating step improved the fiber hydrophilicity. The study showed that 93% of the Chi-coated PCL fiber degraded after 28-day incubation in PBS. Approximately 97.7% and 91.4% of MET were released after 28 days for pH 6.5 and pH 7.4, respectively. Our results indicate that the fabricated electrospun fibers have potential use in GTR due mainly to their hydrophilic, biodegradable and prolonged drug-releasing prospects and subsequent studies involving cellular and in vivo experiments are in progress. © (2021) Society for Biomaterials ; Artificial Organs #20049121

Guided tissue regeneration (GTR) involves the prevention of epithelial down growth in gingival connective tissue by utilizing a barrier membrane, which favors the regeneration of periodontal tissues. This study aims to produce chitosan (Chi)-coated polycaprolactone (PCL) GTR membranes that can prevent inflammation by providing local release of antibiotic/anti-inflammatory drug metronidazole (MET), and can eliminate the need of second periodontal surgery via degradation. PCL fibers (20%) containing 5 and 15 wt.% of MET were fabricated with electrospinning, and then subsequently coated with Chi solutions (5%) for the first time in literature to obtain enhanced fiber biodegradability. Increasing drug concentration caused a decrease in PCL solution viscosity, which resulted in thinner fibers as demonstrated by SEM images. The incorporation of drug as well as the post Chi coating step improved the fiber hydrophilicity. The study showed that 93% of the Chi-coated PCL fiber degraded after 28-day incubation in PBS. Approximately 97.7% and 91.4% of MET were released after 28 days for pH 6.5 and pH 7.4, respectively. Our results indicate that the fabricated electrospun fibers have potential use in GTR due mainly to their hydrophilic, biodegradable and prolonged drug-releasing prospects and subsequent studies involving cellular and in vivo experiments are in progress. © (2021) Society for Biomaterials ; Artificial Organs #20049121

Background: The objective of this study was to digitally evaluate the effect of the cervical emergence of restorations in terms of gingival tissue volume. Materials and methods: In this study, 31 upper front teeth (from canine to canine) were selected and prepared using the biologically oriented preparation technique (BOPT). Each tooth had undergone a change in its provisional process with different emergence profile angles: 30° and 60°. Each sample was digitalised (STL file) using an intraoral scanner. By using various pieces of manipulation software for STL files, a volumetric analysis protocol was carried out. Changes in gingival thickness and position were measured at the buccal and the lingual positions. Results: By increasing the angulation of the emergence profile to 60°, the gingival thickness increased by 0.255 ± 0.381 mm (p = 0.001; t-test) at buccal and by 0.038 ± 0.381 mm at lingual (p = 0.600; t-test). In relation to the gingival height, at buccal, there is an apical displacement of 0.262 ± 0.246 mm (p = 0.001; t-test), and at lingual, there is an apical displacement of 0.390 ± 0.279 mm (p = 0.001; t-test). It was shown that an increase in the provisional emergence profile angle significantly diminishes the gingival height while significantly increasing gingival thickness. The Pearson’s correlation coefficient, r = 0.636, was moderately high and significant (p = 0.001; Pearson). Conclusions: The soft tissue surrounding the BOPT restored tooth evolved according to the prosthetic emergence angle of the provisional restoration, enabling us to plan for an apico-coronal and bucco-lingual displacement of the gingival tissue prior to the definitive restoration.

Background: The objective of this study was to digitally evaluate the effect of the cervical emergence of restorations in terms of gingival tissue volume. Materials and methods: In this study, 31 upper front teeth (from canine to canine) were selected and prepared using the biologically oriented preparation technique (BOPT). Each tooth had undergone a change in its provisional process with different emergence profile angles: 30° and 60°. Each sample was digitalised (STL file) using an intraoral scanner. By using various pieces of manipulation software for STL files, a volumetric analysis protocol was carried out. Changes in gingival thickness and position were measured at the buccal and the lingual positions. Results: By increasing the angulation of the emergence profile to 60°, the gingival thickness increased by 0.255 ± 0.381 mm (p = 0.001; t-test) at buccal and by 0.038 ± 0.381 mm at lingual (p = 0.600; t-test). In relation to the gingival height, at buccal, there is an apical displacement of 0.262 ± 0.246 mm (p = 0.001; t-test), and at lingual, there is an apical displacement of 0.390 ± 0.279 mm (p = 0.001; t-test). It was shown that an increase in the provisional emergence profile angle significantly diminishes the gingival height while significantly increasing gingival thickness. The Pearson’s correlation coefficient, r = 0.636, was moderately high and significant (p = 0.001; Pearson). Conclusions: The soft tissue surrounding the BOPT restored tooth evolved according to the prosthetic emergence angle of the provisional restoration, enabling us to plan for an apico-coronal and bucco-lingual displacement of the gingival tissue prior to the definitive restoration.

Background: The objective of this study was to digitally evaluate the effect of the cervical emergence of restorations in terms of gingival tissue volume. Materials and methods: In this study, 31 upper front teeth (from canine to canine) were selected and prepared using the biologically oriented preparation technique (BOPT). Each tooth had undergone a change in its provisional process with different emergence profile angles: 30° and 60°. Each sample was digitalised (STL file) using an intraoral scanner. By using various pieces of manipulation software for STL files, a volumetric analysis protocol was carried out. Changes in gingival thickness and position were measured at the buccal and the lingual positions. Results: By increasing the angulation of the emergence profile to 60°, the gingival thickness increased by 0.255 ± 0.381 mm (p = 0.001; t-test) at buccal and by 0.038 ± 0.381 mm at lingual (p = 0.600; t-test). In relation to the gingival height, at buccal, there is an apical displacement of 0.262 ± 0.246 mm (p = 0.001; t-test), and at lingual, there is an apical displacement of 0.390 ± 0.279 mm (p = 0.001; t-test). It was shown that an increase in the provisional emergence profile angle significantly diminishes the gingival height while significantly increasing gingival thickness. The Pearson’s correlation coefficient, r = 0.636, was moderately high and significant (p = 0.001; Pearson). Conclusions: The soft tissue surrounding the BOPT restored tooth evolved according to the prosthetic emergence angle of the provisional restoration, enabling us to plan for an apico-coronal and bucco-lingual displacement of the gingival tissue prior to the definitive restoration.

Мета роботи - встановити особливості патоморфологічної картини тканин пародонтального комплексу за умов чотиритижневого введення малих доз опіоїдного анальгетика.Матеріал і методи. Дослідження проведено на 16 безпорідних статевозрілих білих щурах–самцях, яким проводили щоденно, упродовж 28 днів ін’єкції препарату “Налбуфін”, у дозуванні від 0,212 мг/кг до 0,252 мг/кг. Для гістологічного дослідження використали ампутовані сегменти верхньої щелепи та екзартикульовані сегменти нижньої щелепи.Результати. Розвиток запального процесу супроводжувався ураженням клітин шарів епітелію, їх вираженою гіпертрофією, явищами десквамації, кератозу і гіперкератозу. Виявляли інвазію епітелію в набряклу власну пластинку та початкові ознаки руйнування епітеліального прикріплення в ділянці зубо-ясенної борозни. Поліморфноклітинна інфільтрація помірно виражена у власній пластинці слизової оболонки ясен та періодонті. Зміни в гемомікроциркуляторному руслі сполучної тканини проявлялися повнокров’ям, явищами ангіоматозу та дилатації венул. Кісткова тканина слабомінералізована. Цемент кореня зуба негомогенно мінералізований.Висновки. Початкові зміни клітинних ушкоджень переважали в поверхневих шарах м’яких тканин пародонта з послідовним поширенням патологічного процесу в більш глибокі шари, де кісткова тканина, окістя та цемент кореня зуба залишалися практично інтактними. Паралельно зі змінами запального характеру, адекватно розвиваються компенсаторно-пристосувальні реакції в тканинах пародонта на ранніх термінах опіоїдного впливу., Цель работы — установить особенности патоморфологической картины тканей пародонтального комплекса в условиях четырехнедельного введения малых доз опиоидного анальгетика.Материал и методы. Исследование проведено на 16 беспородных половозрелых белых крысах-самцах, которым проводили ежедневно в течение 28 дней инъекции препарата "Налбуфин", в дозе от 0,212 мг/кг до 0,252 мг/кг. Для гистологического исследования использовали ампутированные сегменты верхней челюсти и экзартикулированные сегменты нижней челюсти.Результаты. Развитие воспалительного процесса сопровождалось поражением клеток слоев эпителия, их выраженной гипертрофией, явлениями десквамации, кератоза и гиперкератоза. Наблюдали инвазию эпителия в набухшую собственную пластинку и начальные признаки разрушения эпителиального прикрепления в области зубо-десневой борозды. Полиморфноклеточная инфильтрация умеренно выражена в собственной пластинке слизистой оболочки десны и периодонте. Изменения в гемомикроциркуляторном русле соединительной ткани проявлялись полнокровием, явлениями ангиоматоза и дилатации венул. Костная ткань слабоминерализована. Цемент корня зуба негомогенно минерализирован. Выводы. Начальные изменения клеточных повреждений преобладали в поверхностных слоях мягких тканей пародонта с последовательным распространением патологического процесса в более глубокие слои, где костная ткань, надкостница и цемент корня зуба оставались практически интактными. Параллельно с изменениями воспалительного характера, адекватно развиваются компенсаторно-приспособительные реакции в тканях пародонта на ранних сроках опиоидного воздействия., The objective of the study is to determine the peculiarities of pathomorphological features of the periodontal tissue complex under conditions of inoculation of opioid analgesics in small doses for 4 weeks.Material and methods. The study was conducted on 16 outbred sexually mature white male rats which were injected Nalbuphine in a daily dose from 0.212 mg/kg to 0.252 mg/kg for 28 days. Amputated maxillary segments and exarticulated mandibular segments have been used for histological study.Results. The development of the inflammatory process was accompanied by epithelial cell layers damage, their marked hypertrophy, the phenomena of desquamation, keratosis and hyperkeratosis. Invasion of epithelium in swollen lamina propria and initial signs of the destruction of the epithelial attachment have been detected in the region of the gingival sulcus. Polymorphic cell infiltration is moderately marked in the lamina propria of the gingival mucosa and periodontium. Changes in the microcirculatory bloodstream of the connective tissue were manifested by plethora, phenomena of angiomatosis and dilatation of venules. Osseous tissue of the slightly mineralized. Сementum of the tooth root was non-homogeneously mineralized.Conclusions. Initial changes in cell injuries prevailed in interfacial layers of periodontal soft tissues with subsequent spread of the pathological process in deeper periodontal layers where the osseous tissue, periosteum and cementum of the tooth root remained almost intact. The compensatory-adaptive reactions in periodontal tissues were sufficiently developed in the early stages of opioid exposure along with alterations of the inflammatory character.

В настоящее время широко внедряются в образование инновационные учебные программы в рамках обучения в лицеях, гимназиях, кадетских школах, частных школах, коллегиумах и т.д., что сопряжено с интенсификацией учебно-воспитательного процесса. Цель исследования. Выявить особенности состояния тканей пародонта у школьников 9–16 лет в зависимости от характера учебной нагрузки.

Recently, various biostimulation's effects of low energy laser irradiation have been reported. The present study was designed to examine the effects of low-energy laser irradiation on alveolar bone remodelling during orthodontic tooth movement and finally on formation of new keratinized gingiva.

INTRODUCTION Periodontitis is an inflammatory disease of the supporting tissues of teeth and is a major cause of tooth loss in adults. The onset and progression of periodontal disease is attributed to the presence of elevated levels of a consortium of pathogenic bacteria. Gram negative bacteria, mainly strict anaerobes, play the major role. OBJECTIVE The present study aimed to assess the presence of the main types of microorganisms involved in the aetiopathogenesis of periodontal disease: Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Eikenella corrodens, Treponema denticola, Tanerella forsythia and Prevotella intermedia in different samples collected from the oral cavity of 90 patients diagnosed with periodontitis. METHOD Bacterial DNA detection was performed in diverse biological materials, namely in dental plaque, gingival tissue and saliva, by means of multiplex PCR, a technique that allows simultaneous identification of two different bacterial genomes. RESULTS In the dental plaque of the periodontitis patients, Treponema denticola dominated. In the gingival tissue, Tannerella forsythia and Treponema denticola were the microbiota most frequently detected, whilst in saliva Treponema denticola and Eikenella corrodens were found with the highest percentage. CONCLUSION The identification of microorganisms by multiplex PCR is specific and sensitive. Rapid and precise assessment of different types of periodontopathogens is extremely important for early detection of the infection and consequently for the prevention and treatment of periodontal disease. In everyday clinical practice, for routine bacterial evaluation in patients with periodontal disease, the dental plaque is the most suitable biological material, because it is the richest in periodontal bacteria., Uvod Epidemiološki podaci iz čitavog sveta ukazuju na veliku rasprostranjenost gingivitisa i parodontopatije, oboljenja potpornog aparata zuba. U etiopatogenezi oboljenja parodoncijuma ključnu ulogu igraju različiti rodovi Gram-negativnih bakterija, ponajviše striktnih anaeroba. Cilj rada Cilj rada je bio da se ispita postojanje genoma glavnih parodontopatogenih mikroorganizama Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Eikenella corrodens, Treponema denticola, Tanerella forsythia i Prevotella intermedia u različitim uzorcima poreklom iz usne duplje pacijenata s klinički dijagnostikovanom parodontopatijom. Metod rada Kao biološki materijal u kojem je dokazivano postojanje DNK mikroorganizama korišćeni su zubni plak, tkivo zapaljene gingive i pljuvačka. Za otkrivanje bakterijskog genoma primenjena je multipleks tehnika reakcije lančanog umnožavanja (engl. polymerase chain reaction PCR), odnosno simultana amplifikacija gena dve različite bakterije. Rezultati S manjom ili većom učestalošću, u svim ispitanim uzorcima utvrđeno je postojanje parodontopatogenih mikroorganizama. U zubnom plaku osoba obolelih od parodontopatije najčešći je bio genom vrste Treponema denticola. U tkivu parodoncijuma otkriveno je u najvećem procentu postojanje genoma vrsta Tannerella forsythia i Treponema denticola, što je odlika hroničnog oblika parodontopatije, a u pljuvački ispitanika dominirale su Treponema denticola i Eikinella corrodens. Najmanje ukupno postojanje bakterija je zapaženo u pljuvački. Zaključak Primenjeni metod PCR ima veliku osetljivost i specifičnost. Brzo i precizno otkrivanje mikroorganizama je veoma važno za pravovremeno dijagnostikovanje infekcije, a samim tim i za prevenciju i lečenje parodontopatija. U svakodnevnoj kliničkoj praksi optimalan biološki materijal za dokazivanje parodontopatogena kod osoba obolelih od parodontopatije je zubni plak, koji se smatra pouzdanim pokazateljem zastupljenosti pojedinih bakterija u obolelom parodoncijumu.

Objective: PGE2 is an important factor in pathogenesis of periodontal disease because of bone resorting activity and association with attachment loss. PGE2 and PGE receptor subtypes (EPs) play an important role in modulating bone metabolism via osteoblasts. However, little is known about the effects of PGE2 on cementoblasts. The aims of this study were to determine the expression of EPs on matured cementoblasts and to examine the effect of PGE2 and EPs on their cellar function. Design: Expression of EPs in immortalized mouse cementoblasts (OCCM-30), which were characterized as matured cementoblasts, was determined using RT-PCR. Then effects of PGE2 and EP agonists on mineralization were examined by studying nodule formation with alizarin red S (ALZ) staining. Alkaline phosphatase (ALP) activity with PGE2, EP4 agonist was examined by Bessey-Lowry enzymologic method. Effects of PGE2-EP4 pathway on expression levels of osteocalcin (OCN) and matrix metalloproteinase (MMP)-13 mRNA were examined by real-time RT-PCR. Results: OCCM-30 expressed EP1, 2, 3 and 4 mRNA. PGE2 and EP4 agonist caused downregulation of mineralized nodule formation and ALP activity in OCCM-30. OCN mRNA expression was suppressed and MMP-13 mRNA expression was stimulated via PGE2-EP4 pathway in OCCM-30. Conclusions: Cementoblasts may downregulate their mineralization ability and upregulate MMP-13 production through PGE2-EP4 pathway and may contribute to destruction of connective tissue attachment under inflammatory condition.

INTRODUCTION Periodontitis is an inflammatory disease of the supporting tissues of teeth and is a major cause of tooth loss in adults. The onset and progression of periodontal disease is attributed to the presence of elevated levels of a consortium of pathogenic bacteria. Gram negative bacteria, mainly strict anaerobes, play the major role. OBJECTIVE The present study aimed to assess the presence of the main types of microorganisms involved in the aetiopathogenesis of periodontal disease: Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Eikenella corrodens, Treponema denticola, Tanerella forsythia and Prevotella intermedia in different samples collected from the oral cavity of 90 patients diagnosed with periodontitis. METHOD Bacterial DNA detection was performed in diverse biological materials, namely in dental plaque, gingival tissue and saliva, by means of multiplex PCR, a technique that allows simultaneous identification of two different bacterial genomes. RESULTS In the dental plaque of the periodontitis patients, Treponema denticola dominated. In the gingival tissue, Tannerella forsythia and Treponema denticola were the microbiota most frequently detected, whilst in saliva Treponema denticola and Eikenella corrodens were found with the highest percentage. CONCLUSION The identification of microorganisms by multiplex PCR is specific and sensitive. Rapid and precise assessment of different types of periodontopathogens is extremely important for early detection of the infection and consequently for the prevention and treatment of periodontal disease. In everyday clinical practice, for routine bacterial evaluation in patients with periodontal disease, the dental plaque is the most suitable biological material, because it is the richest in periodontal bacteria., Uvod Epidemiološki podaci iz čitavog sveta ukazuju na veliku rasprostranjenost gingivitisa i parodontopatije, oboljenja potpornog aparata zuba. U etiopatogenezi oboljenja parodoncijuma ključnu ulogu igraju različiti rodovi Gram-negativnih bakterija, ponajviše striktnih anaeroba. Cilj rada Cilj rada je bio da se ispita postojanje genoma glavnih parodontopatogenih mikroorganizama Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Eikenella corrodens, Treponema denticola, Tanerella forsythia i Prevotella intermedia u različitim uzorcima poreklom iz usne duplje pacijenata s klinički dijagnostikovanom parodontopatijom. Metod rada Kao biološki materijal u kojem je dokazivano postojanje DNK mikroorganizama korišćeni su zubni plak, tkivo zapaljene gingive i pljuvačka. Za otkrivanje bakterijskog genoma primenjena je multipleks tehnika reakcije lančanog umnožavanja (engl. polymerase chain reaction PCR), odnosno simultana amplifikacija gena dve različite bakterije. Rezultati S manjom ili većom učestalošću, u svim ispitanim uzorcima utvrđeno je postojanje parodontopatogenih mikroorganizama. U zubnom plaku osoba obolelih od parodontopatije najčešći je bio genom vrste Treponema denticola. U tkivu parodoncijuma otkriveno je u najvećem procentu postojanje genoma vrsta Tannerella forsythia i Treponema denticola, što je odlika hroničnog oblika parodontopatije, a u pljuvački ispitanika dominirale su Treponema denticola i Eikinella corrodens. Najmanje ukupno postojanje bakterija je zapaženo u pljuvački. Zaključak Primenjeni metod PCR ima veliku osetljivost i specifičnost. Brzo i precizno otkrivanje mikroorganizama je veoma važno za pravovremeno dijagnostikovanje infekcije, a samim tim i za prevenciju i lečenje parodontopatija. U svakodnevnoj kliničkoj praksi optimalan biološki materijal za dokazivanje parodontopatogena kod osoba obolelih od parodontopatije je zubni plak, koji se smatra pouzdanim pokazateljem zastupljenosti pojedinih bakterija u obolelom parodoncijumu.

There is a concept of "tooth stability", which, according to dentists, is ensured by the state of periodontal tissue and alveolar bone. When discussing this concept, the experts draw attention to the interdental ligament, passing over the tops of the interdental partitions and connecting the adjacent teeth with the bundle of connective tissue fibers, as well as the severity of interproximal contacts, the teeth axes direction that forms the compensatory curves, and the ratio of intra- and extraalveolar parts of teeth

Objective: PGE2 is an important factor in pathogenesis of periodontal disease because of bone resorting activity and association with attachment loss. PGE2 and PGE receptor subtypes (EPs) play an important role in modulating bone metabolism via osteoblasts. However, little is known about the effects of PGE2 on cementoblasts. The aims of this study were to determine the expression of EPs on matured cementoblasts and to examine the effect of PGE2 and EPs on their cellar function. Design: Expression of EPs in immortalized mouse cementoblasts (OCCM-30), which were characterized as matured cementoblasts, was determined using RT-PCR. Then effects of PGE2 and EP agonists on mineralization were examined by studying nodule formation with alizarin red S (ALZ) staining. Alkaline phosphatase (ALP) activity with PGE2, EP4 agonist was examined by Bessey-Lowry enzymologic method. Effects of PGE2-EP4 pathway on expression levels of osteocalcin (OCN) and matrix metalloproteinase (MMP)-13 mRNA were examined by real-time RT-PCR. Results: OCCM-30 expressed EP1, 2, 3 and 4 mRNA. PGE2 and EP4 agonist caused downregulation of mineralized nodule formation and ALP activity in OCCM-30. OCN mRNA expression was suppressed and MMP-13 mRNA expression was stimulated via PGE2-EP4 pathway in OCCM-30. Conclusions: Cementoblasts may downregulate their mineralization ability and upregulate MMP-13 production through PGE2-EP4 pathway and may contribute to destruction of connective tissue attachment under inflammatory condition.

Kawai M.Y., Ozasa R., Ishimoto T., et al. Periodontal Tissue as a Biomaterial for Hard-Tissue Regeneration following bmp-2 Gene Transfer. Materials, 15, 3, 993. https://doi.org/10.3390/ma15030993., The application of periodontal tissue in regenerative medicine has gained increasing interest since it has a high potential to induce hard-tissue regeneration, and is easy to handle and graft to other areas of the oral cavity or tissues. Additionally, bone morphogenetic protein-2 (BMP-2) has a high potential to induce the differentiation of mesenchymal stem cells into osteogenic cells. We previously developed a system for a gene transfer to the periodontal tissues in animal models. In this study, we aimed to reveal the potential and efficiency of periodontal tissue as a biomaterial for hard-tissue regeneration following a bmp-2 gene transfer. A non-viral expression vector carrying bmp-2 was injected into the palate of the periodontal tissues of Wistar rats, followed by electroporation. The periodontal tissues were analyzed through bone morphometric analyses, including mineral apposition rate (MAR) determination and collagen micro-arrangement, which is a bone quality parameter, before and after a gene transfer. The MAR was significantly higher 3–6 d after the gene transfer than that before the gene transfer. Collagen orientation was normally maintained even after the bmp-2 gene transfer, suggesting that the bmp-2 gene transfer has no adverse effects on bone quality. Our results suggest that periodontal tissue electroporated with bmp-2 could be a novel biomaterial candidate for hard-tissue regeneration therapy.

Kawai M.Y., Ozasa R., Ishimoto T., et al. Periodontal Tissue as a Biomaterial for Hard-Tissue Regeneration following bmp-2 Gene Transfer. Materials, 15, 3, 993. https://doi.org/10.3390/ma15030993., The application of periodontal tissue in regenerative medicine has gained increasing interest since it has a high potential to induce hard-tissue regeneration, and is easy to handle and graft to other areas of the oral cavity or tissues. Additionally, bone morphogenetic protein-2 (BMP-2) has a high potential to induce the differentiation of mesenchymal stem cells into osteogenic cells. We previously developed a system for a gene transfer to the periodontal tissues in animal models. In this study, we aimed to reveal the potential and efficiency of periodontal tissue as a biomaterial for hard-tissue regeneration following a bmp-2 gene transfer. A non-viral expression vector carrying bmp-2 was injected into the palate of the periodontal tissues of Wistar rats, followed by electroporation. The periodontal tissues were analyzed through bone morphometric analyses, including mineral apposition rate (MAR) determination and collagen micro-arrangement, which is a bone quality parameter, before and after a gene transfer. The MAR was significantly higher 3–6 d after the gene transfer than that before the gene transfer. Collagen orientation was normally maintained even after the bmp-2 gene transfer, suggesting that the bmp-2 gene transfer has no adverse effects on bone quality. Our results suggest that periodontal tissue electroporated with bmp-2 could be a novel biomaterial candidate for hard-tissue regeneration therapy.