No / Infection is the major reason of GTR/GBR membrane failure in clinical application. In this work, we developed GTR/GBR nanofiber membranes with localized drug delivery function to prevent infection. Metronidazole (MNA), an antibiotic, was successfully incorporated into electrospun polycaprolactone (PCL) nanofibers at different concentrations (0, 1, 5, 10, 20, 30, and 40 wt% polymer). To obtain the optimum anti-infection membrane, we systematically investigated the physical-chemical and mechanical properties of the nanofiber membranes with different drug contents. The interaction between PCL and MNA was identified by molecular dynamics simulation. MNA released in a controlled, sustained manner over 2 weeks and the antibacterial activity of the released MNA remained. The incorporation of MNA improved the hydrophilicity and in vitro biodegradation rate of PCL nanofibers. The nanofiber membranes allowed cells to adhere to and proliferate on them and showed excellent barrier function. The membrane loaded with 30% MNA had the best comprehensive properties. Analysis of subcutaneous implants demonstrated that MNA-loaded nanofibers evoked a less severe inflammatory response than pure PCL nanofibers. These results demonstrate the potential of MNA-loaded nanofiber membranes as GTR/GBR membrane with antibacterial and anti-inflammatory function for extensive biomedical applications.

Yes / Infection is the major reason for guided tissue regeneration/guided bone regeneration (GTR/GBR) membrane failure in clinical application. In this work, we developed GTR/GBR membranes with localized drug delivery function to prevent infection by electrospinning of poly(ε-caprolactone) (PCL) and gelatin blended with metronidazole (MNA). Acetic acid (HAc) was introduced to improve the miscibility of PCL and gelatin to fabricate homogeneous hybrid nanofiber membranes. The effects of the addition of HAc and the MNA content (0, 1, 5, 10, 20, 30, and 40 wt.% of polymer) on the properties of the membranes were investigated. The membranes showed good mechanical properties, appropriate biodegradation rate and barrier function. The controlled and sustained release of MNA from the membranes significantly prevented the colonization of anaerobic bacteria. Cells could adhere to and proliferate on the membranes without cytotoxicity until the MNA content reached 30%. Subcutaneous implantation in rabbits for 8 months demonstrated that MNA-loaded membranes evoked a less severe inflammatory response depending on the dose of MNA than bare membranes. The biodegradation time of the membranes was appropriate for tissue regeneration. These results indicated the potential for using MNA-loaded PCL/gelatin electrospun membranes as anti-infective GTR/GBR membranes to optimize clinical application of GTR/GBR strategies.

<p>Uobičajeni pristup i testiranju biolo&scaron;kog pona&scaron;anja materijala je da se počne sa jednostavnim in vitro testovima baziranim na ćelijskim kulturama. In vitro testovi citotoksičnosti su danas jedan od osnovnih načina za procenu biolo&scaron;kog odgovora na materijal jer su brži, lak&scaron;i za ponavljanje, ocenjivanje i jeftiniji u odnosu na eksperimente koji se izvode na životinjama i ljudima. Koriste se kao neka vrsta skrining testova za procenu biolo&scaron;ke sigurnosti materijala. Za razliku od ćelijskih kultura, istraživanja koja uključuju eksperimentalne životinje pružaju bolji uvid u biokompatibilnost materijala, zbog mogućnosti praćenja kompleksnog imunolo&scaron;kog odgovora živog organizma. Smatraju se neophodnim za ocenu bilo&scaron;kih odgovora na novi materijal, pre nego &scaron;to se on upotrebi na ljudima. Mnogi aspekti biolo&scaron;kog odgovora ne mogu biti reprodukovani in vitro testovima uključujući krvne interakcije, zarastanje rana, reakcije preosetljivosti, karcinogenezu, hroničnu inflamaciju. Eksperimenti na životinjama pružaju informacije o ovim tipovima efekata bez izlaganja ljudi riziku. Cilj ovog istraživanja bio je da se oceni biokompatibilnost objekata od polimera na bazi epoksi smole Accura&reg; ClearVue&trade; (hemijski sastav: 4,4&rsquo;- izopropilidendicikloheksanol, produkti oligomerne reakcije sa 1-hlor-2,3- epoksipropanom(40-65%), sme&scaron;а triaril-sulfonijum soli (50% propilen-karbonata i 50% triaril-sulfonijum heksafluoroantimonatnih soli) (1-10%) i 3-etil-3hidroksimetil-oksetan(10-20%). U oceni citotoksičnosti materijala Accura&reg; ClearVue&trade; kori&scaron;ćeni su agar diguzioni i MTT test. Oba testa rađena sun a ćelijskim kulturama L929 (mi&scaron;iji fibroblasti) i MRC-5 (humani fibroblasti). Ocena biokompatibilnosti testiranog materijala vr&scaron;ena je na osnovu urađenog testa iritacije oralne mukoze na modelu bukalne kesice hrčka, &scaron;to je definisano standardom ISO 10993-10:2010. Biokompatibilnost materijala ispitana je i implantacijom uzoraka u potkožno tkivo dorzuma pacova soja Wistar.</p> / <p>Uobičajeni pristup i testiranju biolo&scaron;kog pona&scaron;anja materijala je da se počne sa jednostavnim in vitro testovima baziranim na ćelijskim kulturama. In vitro testovi citotoksičnosti su danas jedan od osnovnih načina za procenu biolo&scaron;kog odgovora na materijal jer su brži, lak&scaron;i za ponavljanje, ocenjivanje i jeftiniji u odnosu na eksperimente koji se izvode na životinjama i ljudima. Koriste se kao neka vrsta skrining testova za procenu biolo&scaron;ke sigurnosti materijala. Za razliku od ćelijskih kultura, istraživanja koja uključuju eksperimentalne životinje pružaju bolji uvid u biokompatibilnost materijala, zbog mogućnosti praćenja kompleksnog imunolo&scaron;kog odgovora živog organizma. Smatraju se neophodnim za ocenu bilo&scaron;kih odgovora na novi materijal, pre nego &scaron;to se on upotrebi na ljudima. Mnogi aspekti biolo&scaron;kog odgovora ne mogu biti reprodukovani in vitro testovima uključujući krvne interakcije, zarastanje rana, reakcije preosetljivosti, karcinogenezu, hroničnu inflamaciju. Eksperimenti na životinjama pružaju informacije o ovim tipovima efekata bez izlaganja ljudi riziku. Cilj ovog istraživanja bio je da se oceni biokompatibilnost objekata od polimera na bazi epoksi smole Accura&reg; ClearVue&trade; (hemijski sastav: 4,4&rsquo;- izopropilidendicikloheksanol, produkti oligomerne reakcije sa 1-hlor-2,3- epoksipropanom(40-65%), sme&scaron;a triaril-sulfonijum soli (50% propilen-karbonata i 50% triaril-sulfonijum heksafluoroantimonatnih soli) (1-10%) i 3-etil-3hidroksimetil-oksetan(10-20%). U oceni citotoksičnosti materijala Accura&reg; ClearVue&trade; kori&scaron;ćeni su agar diguzioni i MTT test. Oba testa rađena sun a ćelijskim kulturama L929 (mi&scaron;iji fibroblasti) i MRC-5 (humani fibroblasti). Ocena biokompatibilnosti testiranog materijala vr&scaron;ena je na osnovu urađenog testa iritacije oralne mukoze na modelu bukalne kesice hrčka, &scaron;to je definisano standardom ISO 10993-10:2010. Biokompatibilnost materijala ispitana je i implantacijom uzoraka u potkožno tkivo dorzuma pacova soja Wistar.</p> / <p>The usual approach in testing biological behavior of materials is to start with simple in vitro tests based on cell cultures. In vitro cytotoxicity tests are one of the basic methods of assessing the biological response to material because they are faster, cheaper, easier for repeating and evaluating compared to experiments carried out on animals and humans. They are used as a kind of screening test for evaluating the biosafety of materials. Unlike cell culture, studies involving experimental animals provide better insight into the biocompatibility of materials due to the possibility of monitoring the complex immune response of a living organism. They are considered necessary for assessing the biological response to new material before it is used on humans. Many aspects of a biological response cannot be reproduced with in vitro tests, including blood interaction, wound healing, hypersensitivity reactions, carcinogenesis, chronic inflammation. Animal experiments provide information about these types of effects without exposing humans to risk.&nbsp; The aim of this study was to evaluate the biocompatibility of polymer objects on the basis of epoxy resins Accura&reg; ClearVue &trade; (chemical composition: 4.4&#39; Isopropylidenedicyclohexanol, oligomeric reaction products with 1-chloro-2.3-epoxypropane (40-65%), a mixture of triaryl sulfonium salt (50% propylene carbonate and 50% of a triarylsulfonium hexafluoroantimonate salt) (1- 10%) and 3-ethyl-3-hydroxymethyl-oxetane (10-20%). In the assessment of the cytotoxicity of materials Accura&reg; ClearVue &trade; agar diffusion and MTT tests were used. Both tests were conducted on cell cultures L929 (mouse fibroblasts) and MRC-5 (human fibroblasts). An assessment of the biocompatibility of the tested material was done on the basis of an oral mucosa irritation test on a hamster cheek pouch as defined by ISO 10993-10: 2010. The biocompatibility of the material was also tested with the implantation of a samples into the dorsal subcutaneous tissue of a Wistar rats. The subcutaneous implantation test, as one of the most reliable methods for assessing the biocompatibility of dental materials, is defined by ISO 10993-6: 2010. The study was conducted on 30 rats which were sacrificed in groups</p>

The relatively new and still growing field of 3D-printing has opened up the possibilities to manufacture patient-specific medical devices with high geometrical accuracy in a precise and quick manner. Additionally, biocompatible materials are a demand for all medical applications while biodegradability is of importance when developing scaffolds for tissue growth for instance. With respect to this, this project consisted of developing biocompatible and bioresorbable polymer blend and composite filaments, for fused deposition modeling (FDM) printing. Poly(lactic acid) (PLA) and polycaprolactone (PCL) were used as supporting polymer matrix while hydroxyapatite (HA), a calcium phosphate with similar chemical composition to the mineral phase of human bone, was added to the composites to enhance the biological activity. PLA and PCL content was varied between 90–70 wt% and 10-30 wt%, respectively, while the HA content was 15 wt% in all composites. All materials were characterized in terms of mechanical properties, thermal stability, chemical composition and morphology. An accelerated degradation study of the materials was also executed in order to investigate the degradation behavior as well as the impact of the degradation on the above mentioned properties. The results showed that all processed materials exhibited higher mechanical properties compared to the human trabecular bone, even after degradation with a mass loss of around 30% for the polymer blends and 60% for the composites. It was also apparent that the mineral accelerated the polymer degradation significantly, which can be advantageous for injuries with faster healing time, requiring only support for a shorter time period.

<p>Već izvesno vreme u stručnoj literaturi vodi se rasprava o biokompatibilnosti materijala koji se koriste u periapikalnoj hirurgiji. Pored biokompatibilnosti, od materijala za retrogradnu opturaciju kanala korena zuba se očekuje da spreči prodor bakterija iz kanalnog sistema u okolna tkiva. Kvalitetno rubno zaptivanje, odnosno adekvatna marginalna adaptacija su među najznačajnijim faktorima za dugoročan uspeh tretmana. Cilj ovog istraživanja je bio ispitati biokompatibilnost i utvrditi da li postoji razlika u biokompatibilnosti između mineral-trioksid agregata, trikalcijum-silikatnog cementa i amalgama na osnovu tri standadna testa citotoksičnosti, kao i utvrditi marginalnu adaptaciju ispitivanih materijala za retrogradno zatvaranje kanala korena zuba. Materijali i metode: Eksperimentalni deo istraživanja je podeljen na dva dela. U prvom delu istraživanja je vr&scaron;eno ispitivanje biokompatibilnosti materijala, dok je u drugom delu vr&scaron;eno ispitivanje marginalne adaptacije na osnovu mikrofotografija dobijenih skening elektronskim mikroskopom. Ispitivanje biokompatibilnosti je izvr&scaron;eno na dve ćelijske linije, liniji mi&scaron;jih fibroblasta (L929) i liniji humanih fibroblasta (MRC-5). U eksperimentima su kori&scaron;ćene samo žive (vijabilne) ćelije. Broj ćelija i njihova vijabilnost je određena testom odbacivanja boje sa 0,1% tripan plavim. Vijabilnost ćelija kori&scaron;ćenih u eksperimentu je bila veća od 90%. Biokompatibilnost sve tri vrste materijala je ispitana na osnovu standardnih testova biokompatibilnosti: DET test, MTT test, Agar difuzioni test. Ispitivanje marginalne adaptacije je sprovedeno na 90 ekstrahovanih jednokorenih zuba interkaninog sektora gornje vilice sa intaktnom pulpom, zavr&scaron;enim rastom korena, bez frakture i resorpcije korena zuba. Izvr&scaron;ena je endodontska obrada svih zuba i nakon toga su zubi ostavljeni u vlažnoj sredini na 48h, da bi se sprečile frakture prilikom sečenja. Nakon mehaničko medikamentozne obrade i opturacije kanala korena zuba je vr&scaron;ena resekcija vrha korena zuba 3mm, a nakon toga su svi zubi preparisani do dubine od 3 mm unutar kanala, ultrazvučnim nastavcima (EMS, miniMaster Piezon scaler). Zubi su naizmenično podeljeni u 3 grupe (30 zuba po grupi). Prvu grupu čine zubi kojima je apikalni kavitet biti ispunjen amalgamom, u drugoj grupi, apikalni kavitet je ispunjen MTA, a u trećoj trikalcijum-silikatnim cementom. Nakon retrogradne opturacije, zubi su ostavljeni u vlažnoj sredini 48h, do potpunog vezivanja ispitivanih materijala. Nakon vezivanja ispitivanih materijala, zubi su sečeni longitudinalno, finom dijamantskom &scaron;ajbnom. Marginalna adaptacija ispitivanih materijala je procenjena skening elektronskim mikroskopom (SEM). Pripremljeni uzorci su posmatrani pod uvećanjima 30x, 40x, 80x i 100x. Uvećanje 30x je rađeno radi prikaza celokoupnog retrogradnog punjenja na jednom snimku, tj. spoja materijal-zub. Nakon toga je napravljeno vi&scaron;e uzastopnih snimaka sauvećanjem 80x do pune dužine materijala. Na taj način je utvrđeno postojanje i izvr&scaron;eno merenje marginalne pukotine u mikrometrima. Merenja ukupne dužine marginalne pukotine u mikrometrima u 5 tačaka sa obe strane preparata su vr&scaron;ena u softverskoj aplikaciji Image J software (National Institutes of Health, Bethesda, USA). Tačke su izabrane tako da tačka 1a i tačka 5a predstavljaju gornju i donju ivicu preparata. Tačka 3a predstavlja sredinu rastojanja između tačke 1a i tačke 5a. Tačka 2a i tačka 4a predstavljaju sredinu razmaka između tačke 1a i 3a, odnosno 3a i a5. Tačke 1b-5b su naspramne tačke. Rezultati biokompatibilnosti ukazuju na visok stepen ćelijske kompatibilnosti svih ispitivanih materijala. Međutim, DET testomnije utvrđena statistički značajna razlika u citotoksičnosti između istovetnih ispitivanih materijala u obe ćelijske linije, niti između sva tri ispitivana materijala u obe ćelijske kulture.Poređenjem rezultata MTT testa nakon 24h i 48h, kao i nakon 48h i 72h uočava se da su dobijene srednje vrednosti indeksa citotoksičnosti kod sva tri ispitivana materijala i na obe ćelijske linije manje nakon 48h, odnosno nakon 72h, &scaron;to ukazuje na oporavak ćelijskog metabolizma. Poređenjem rezultata nakon 24h i nakon 72h, uočava se znatno veći pad vrednosti indeksa citotoksičnosti nakon 72h kod sva tri ispitivana materijala i na obe ćelijske linije. U kulturi ćelija MRC5, kod sva tri ispitivana materijala postoji statistički značajna razlika između indeksa citotoksičnosti izmerenog nakon 24h i nakon 72h, kao i u kulturi ćelija L929. Agar difuzionim testom nije uočena dekolorizacija, niti liza ćelija ispod ispitivanih materijala. Ćelijski odgovor je 0/0 &scaron;to ukazuje da ovim testom nije utvrđeno postojanje citotoksičnog efekta ispitivanih materijala na ćelijske linije L929 i MRC-5. Ispitivanje marginalne adaptacije materijala je vr&scaron;eno na osnovu mikrofotografija dobijenih skening elektronskim mikroskopom.. Najpre su testirane razlike na prvoj tački merenja. Rezultati ovog testa pokazuju da postoje značajne razlike između materijala i da amalgam ima značajno vi&scaron;e vrednosti izmerenih pukotina u odnosu na preostala dva materijala, dok se vrednosti za MTA i biodentin međusobno značajno ne razlikuju. Kao jo&scaron; jedna referentna tačka uzeta je tačka merenja 5. I u odnosu na vrednosti u ovoj tački merenja zabeležene su značajne razlike između materijala. Post hoc Mann-Whitney test pokazuje da se amalgam značajno razlikuje od preostala dva materijala, dok nema značajnih razlika između MTA i biodentina. Na osnovu medijane može se videti da amalgam ima niže vrednosi u ovoj tački merenja u odnosu na preostala dva materijala. U tačkama 2-4, kao i u tačkama 1-5 (ukupno), ne postoji statistički značajna razlika u marginalnoj adaptaciji ispitivanih materijala. Rezultati biokompatibilnosti ukazuju na visok stepen ćelijske kompatibilnosti svih ispitivanih materijala. Rezultati sva tri testa pokazuju da ne postoji statistički značajna razlika u citotoksičnosti između ispitivanih materijala. MTT test pokazuje da u obe ćelijske kulture, kod istovetnih ispitivanih materijala postoji statistički značajna razlika između indeksa citotoksičnosti izmerenog nakon 24h i nakon 72h. Rezultati ispitivanja marginalne adaptacije pokazuju da u tački 1 najgore zaptiva amalgam, dok izmedju MTA i biodentina nema razlike. U tački 5 najbolje zaptiva amalgam.</p> / <p>Biocompatibility of materials, deployed in periapical surgery, has been a subject of debate in referential literature for some time now. Apart from biocompabillity, root end filling materials are expected to prevent bacteria from entering the surrounding tissue from canal system. The most important factors for successful long term treatment include marginal seal, i.e. adequate marginal adaptation. The aim of this research was to examine biocompatibility and establish the potential difference in biocompatibility between mineral trioxide aggregate, tricalcium silicate cement and dental amalgam according to three cytotoxicity tests, but also to corroborate marginal adaptation of the materials in question for retrograde seal of a root canal. Materials and methods: The experimental part of the research is divided in two parts. In the first part of the research biocompatibility of the materials was examined, while the examination of the marginal adaptation based on the micro images from scanning electron microscope was conducted in the second part. The examination of biocompatibility was executed on two cell lines, mouse fibroblast cell line (L929) and human cell line (MRC-5).Biocompatibility of all three types of material was examined based on three standard biocompatibility tests: DET test, MTT test, Agar diffusion test.The examination of marginal adaptation was carried out on 90 single-rooted tooth extractied human teeth of the intercanine sector of maxilla with intact pulp, mature apices, without root fractures or resorption. All teeth were endodontically treated. After the extirpation, irrigation and opturation, the resection of 3mm of root apex and retrograde preparation with ultrasonic instruments up to 3 mm depth inside the canal was done. Teeth were divided in three groups alternately. The First group include teeth which apical cavitation was filled with amalgam, in the Second group apical cavitation was filled with MTA, and in the Third group with tricalcium silicate cement. After the complete setting of the materials, teeth were cut in longitudinal manner, with fine, diamond tool. Marginal adaptation of the materials was assessed through scanning electron microscope (SEM). Software application Image J software was deployed to measure the total length of marginal fissure in micrometers in 5 pointson both sides of the preparation . The results of biocompatibility indicate high degree of cell compatibility of all tested materials. DET test did not assert any statistically significant difference in cytotoxicity between the same tested materials in both cell lines, nor between all three tested materials in both cell cultures. Comparing the results of MTT test after 24h and 48h, and 48h and 72h, it is noted that middle value of cytotoxicity index with all three tested materials and on both cell lines is lower after 48h, and after 72h, indicating the recovery of cell metabolism. In both cell cultures, with all three tested materials there is statistically significant difference between measured cytotoxicity indices after 24h and after 72h. Agar diffusion test did not show decolorization, nor cell lysis underneath the tested materials, which means that cytotoxic effect was not asserted on cell lines L929 i MRC-5. The examination of marginal adaptation was conducted according to micro images gained by scanning electron microscope. The results in the measure point 1 indicate there are significant differences between materials, and amalgam has significantly higher values of the measured fissures in relation to remaining two materials, whereas values for MTA and biodentine do not differ significantly. In measure point 5 significant differences were noted. Post hoc Mann-Whitney test shows that amalgam has lower values of the tested fissures in this measure point in relation to two other materials, while there were no significant differences between MTA i biodentine. In points 2-4, as well as points 1-5 (in total), there were no statistically significant differences in marginal adaptation of the examined materials. The results of all three tests show that there is no statistically significant difference in cytotoxicity between examined materials. MTT test shows that there is, in both cell cultures, with the same examined materials , statistically significant difference between cytotoxicity indices measured after 24h and after 72h. The results of the examination of marginal adaptation show that in point 1 amalgam has the worst seal, whereas between MTA and biodentine there is no difference. In point 5 amalgam has the best seal.</p>

Yes / The peripheral nervous system has a limited innate capacity for self-repair following injury, and surgical intervention is often required. For injuries greater than a few millimeters autografting is standard practice although it is associated with donor site morbidity and is limited in its availability. Because of this, nerve guidance conduits (NGCs) can be viewed as an advantageous alternative, but currently have limited efficacy for short and large injury gaps in comparison to autograft. Current commercially available NGC designs rely on existing regulatory approved materials and traditional production methods, limiting improvement of their design. The aim of this study was to establish a novel method for NGC manufacture using a custom built laser-based microstereolithography (muSL) setup that incorporated a 405 nm laser source to produce 3D constructs with approximately 50 mum resolution from a photocurable poly(ethylene glycol) resin. These were evaluated by SEM, in vitro neuronal, Schwann and dorsal root ganglion culture and in vivo using a thy-1-YFP-H mouse common fibular nerve injury model. NGCs with dimensions of 1 mm internal diameter x 5 mm length with a wall thickness of 250 mum were fabricated and capable of supporting re-innervation across a 3 mm injury gap after 21 days, with results close to that of an autograft control. The study provides a technology platform for the rapid microfabrication of biocompatible materials, a novel method for in vivo evaluation, and a benchmark for future development in more advanced NGC designs, biodegradable and larger device sizes, and longer-term implantation studies.