ABSTRACT
OBJECTIVES: The current study aimed to perform an in vivo examination using a critical-size periodontal canine model to investigate the capability of a 3D-printed soft membrane for guided tissue regeneration (GTR). This membrane is made of a specific composition of gelatin, elastin, and sodium hyaluronate that was fine-tuned and fully characterized in vitro in our previous study. The value of this composition is its potential to be employed as a suitable replacement for collagen, which is the main component of conventional GTR membranes, to overcome the cost issue with collagen. METHODS: Critical-size dehiscence defects were surgically created on the buccal surface of the roots of canine bilateral mandibular teeth. GTR treatment was performed with the 3D-printed membrane and two commercially available collagen membranes (Botiss Jason® and Smartbrane-Regedent membranes) and a group without any membrane placement was considered as the control group. The defects were submerged with tension-free closure of the gingival flaps. Histologic and histometric analyses were employed to assess the periodontal healing over an 8-week experimental period. RESULTS: Histometric evaluations confirmed higher levels of new bone formation in the 3D-printed membrane group. Moreover, in all defects treated with the membranes, the formation of periodontal tissues, bone, periodontal ligaments, and cementum was observed after 8 weeks, while in the control group, only connective tissue was found in the defect sites. There was no clinical sign of inflammation or recession of gingiva in any of the groups. SIGNIFICANCE: The 3D-printed gelatin/elastin/sodium hyaluronate membrane can be safe and effective for use in GTR for periodontal tissue regeneration therapies, with better or comparable results to the commercial collagen membranes.
ABSTRACT
Between September 2019 and December 2023, a total of 612 wild birds representing 16 orders, 33 families, 60 genera, and 78 species from nine provinces of Iran with different climates namely Hamedan (n = 54), Sistan-va-Baluchestan (n = 372), Kerman (n = 73), South Khorasan (n = 52), Mazandaran (n = 7), Chaharmahal-va-Bakhtiari (n = 2), Gilan (n = 2), Golestan (n = 18), North Khorasan (n = 9), and Razavi Khorasan (n = 23) were examined for chewing lice infestation. Naked eye examination revealed that 58 birds (9.5%) were infested with at least one chewing louse species. Collected lice specimens belonged to 28 species from the families Philopteridae, Menoponidae and Laemobothriidae including Strigiphilus strigis (n = 55, 15.6%), Falcolipeurus quadripustulatus (n = 41, 11.6%), Craspedorrhynchus platystomus (n = 40, 11.3%), Colpocephalum turbinatum (n = 36, 10.2%), Laemobothrion maximum (n = 25, 7.1%), Nosopon lucidum (n = 20, 5.6%), Degeeriella fulva (n = 18, 5.1%), Colpocephalum eucarenum (n = 16, 4.5%), Laemobothrion vulturis (n = 15, 4.2%), Anaticola crassicornis (n = 13, 3.7%), Craspedorrhynchus aquilinus (n = 9, 2.5%), Degeeriella fusca (n = 7, 2.0%), Aegypoecus trigonoceps (n = 7, 2.0%), Quadraceps obscurus (n = 6, 1.7%), Colpocephalum impressum (n = 6, 1.7%), Trinoton querquedulae (n = 6, 1.7%), Colpocephalum heterosoma (n = 5, 1.4%), Colpocephalum nanum (n = 5, 1.4%), Lunaceps holophaeus (n = 4, 1.1%), Quadraceps spp. (n = 4, 1.1%), Actornithophilus uniseriatus (n = 2, 0.6%), Nosopon chanabense (n = 2, 0.6%), Actornithophilus cornutus (n = 1, 0.3%), Cuclotogaster heterographus (n = 1, 0.3%), Falcolipeurus suturalis (n = 1, 0.3%), Laemobothrion atrum (n = 1, 0.3%), Colpocephalum gypsi (n = 1, 0.3%), and Rallicola cuspidatus (n = 1, 0.3%). All of these species except six, i.e., Trinoton spp., C. aquilinus, L. vulturis, L. maximum, C. impressum, C. turbinatum, and C. heterographus are recorded for the first time from Iran. This study is the largest epidemiological study to date performed in the country. Data reported herein contribute to our knowledge about diversity of avian chewing lice from wild birds in Iran. In this paper, an updated checklist of louse species reported from Iran according to their avian hosts is presented.
ABSTRACT
OBJECTIVES: There are complications in applying regenerative strategies at the interface of hard and soft tissues due to the limited designs of constructs that can accommodate different cell types in different sites. The problem originates from the challenges in the adhesion of dissimilar materials, such as polymers and hydrogels, that can be suitable for regenerating different tissues such as bone and soft tissues. This paper presents a design of a new hybrid construct in which a polymer (polycaprolactone (PCL)) membrane firmly adheres to a layer of hydrogen (gelatin). METHODS: PCL membranes with defined size and porosity were fabricated using 3D printing. The gelatin layer was attached to the PCL membranes using the aminolysis procedure. We have examined this construct for the application of Guided Bone Regeneration (GBR) as a typical surgical regenerative procedure of the oral cavity at the interface of bone and soft tissue. Complete in vitro and in vivo investigations on canine tibia bone defects have been performed. Histological analyses for fibrosis morphometric and bone morphometric evaluation, as well as bone-fibrosis histological grading and CBCT imaging, were conducted. RESULTS: Chemical and morphological studies of the membrane proved that gelatin was uniformly attached to the aminolyzed PCL membranes. The in vitro and in vivo studies indicated the membrane's biocompatibility, mechanical stability, and barrier function for the GBR application. Furthermore, in vitro study showed that the membranes could improve osteogenesis and the regeneration of bone defects. The results illustrated that the mean bone density in the membrane groups was about three times more than that of the control group. SIGNIFICANCE: The fabricated 3D-printed hybrid Gelatin/PCL bi-layered membrane can be a good candidate for interfacial tissue engineering and a promising membrane for GBR procedure.
