Evolution Of Implants Research Articles

A burst of genomic innovation at the origin of placental mammals mediated embryo implantation

The origin of embryo implantation in mammals ~148 million years ago was a dramatic shift in reproductive strategy, yet the molecular changes that established mammal implantation are largely unknown. Although progesterone receptor signalling predates the origin of mammals and is highly conserved in, and critical for, successful mammal pregnancy, it alone cannot explain the origin and subsequent diversity of implantation strategies throughout the placental mammal radiation. MiRNAs are known to be flexible and dynamic regulators with a well-established role in the pathophysiology of mammal placenta. We propose that a dynamic core microRNA (miRNA) network originated early in placental mammal evolution, responds to conserved mammal pregnancy cues (e.g. progesterone), and facilitates species-specific responses. Here we identify 13 miRNA gene families that arose at the origin of placental mammals and were subsequently retained in all descendent lineages. The expression of these miRNAs in response to early pregnancy molecules is regulated in a species-specific manner in endometrial epithelia of species with extreme implantation strategies (i.e. bovine and human). Furthermore, this set of miRNAs preferentially target proteins under positive selective pressure on the ancestral eutherian lineage. Discovery of this core embryo implantation toolkit and specifically adapted proteins helps explain the origin and evolution of implantation in mammals.

Хирургия пролапса тазовых органов вагинальным доступом в специализированном центре: эволюция имплантов от «XL до XS»

Хирургия пролапса тазовых органов вагинальным доступом в специализированном центре: эволюция имплантов от «XL до XS»

Evolution of implants and advancements for osseointegration: A narrative review

Since ancient times, reduction and internal fixation has been applied to restore skeletal integrity. Despite advances in the understanding of fracture healing, the risk of complication such as implant loosening or implant-related infection still depicts a challenging complication. Nowadays, a great deal of research is devoted to unreveal the impact of implant surface modifications on osteogenic processes to enhance bone consolidation and osseointegration. This narrative review is aimed to (1) show the evolution and already achieved milestones of implant optimization, and (2) to outline the key factors that contribute to an enhanced osseointegration. Different physical and chemical roughening techniques are currently applied in various studies. Surface patterning on the nanoscale has been found to be an essential factor for the biological response, achievable by e.g. anodisation or laser texturing. Besides surface roughening, also different coating methods are vastly investigated. Next to metal or inorganic compounds as coating material, a variety of biomolecules is currently studied for their osteosupportive capacities. Osseointegration can be improved by surface modification on the micro and nanoscale. Bioactive agents can further improve the osseointegration potential. Used agents at the moment are e.g. inorganic compounds, growth factors (BMPs and non-BMPs) and antiresorptive drugs. The advancement in research on new implant generations therefore aims at actively supporting osseointegration processing.

X-ray computed microtomography datasets for osteogenic nanofibrous coated titanium implants

Surface modifications of titanium implant influences the quality of osseointegration and are associated with favourable treatment prognosis in orthopaedic and cranio-maxillofacial cases. Hence, unlike previous works, the peri-implant region details of our novel osteogenic nanofibrous coated implants placed in rabbits (n = 6 + 1) were recorded over a 12-week period using a micro-CT imaging system. In this unique contribution, we have created a computed tomography (CT) library of rabbit’s tibiae anatomy with osteogenic nanofibrous coated/uncoated implants and are introductory useful assets for investigating the correlation between osteogenic nanofibers coated implants and its effect on improved osseointegration. Apart from using this CT dataset to conduct serial 2D image studies, three-dimensional (3D) reconstructions, assessing segmentation algorithms and developing adequate image quantitation tools, there may be positive applications of these in comparative investigations of similar or related preclinical as well as future clinical studies, further design planning, development etc. required for evolution of implants beyond the present state of art.

Evolutionary transcriptomics implicates HAND2 in the origins of implantation and regulation of gestation length

The developmental origins and evolutionary histories of cell types, tissues, and organs contribute to the ways in which their dysfunction produces disease. In mammals, the nature, development and evolution of maternal-fetal interactions likely influence diseases of pregnancy. Here we show genes that evolved expression at the maternal-fetal interface in Eutherian mammals play essential roles in the evolution of pregnancy and are associated with immunological disorders and preterm birth. Among these genes is HAND2, a transcription factor that suppresses estrogen signaling, a Eutherian innovation allowing blastocyst implantation. We found dynamic HAND2 expression in the decidua throughout the menstrual cycle and pregnancy, gradually decreasing to a low at term. HAND2 regulates a distinct set of genes in endometrial stromal fibroblasts including IL15, a cytokine also exhibiting dynamic expression throughout the menstrual cycle and gestation, promoting migration of natural killer cells and extravillous cytotrophoblasts. We demonstrate that HAND2 promoter loops to an enhancer containing SNPs implicated in birth weight and gestation length regulation. Collectively, these data connect HAND2 expression at the maternal-fetal interface with evolution of implantation and gestational regulation, and preterm birth.

Decidualization of Human Endometrial Stromal Fibroblasts is a Multiphasic Process Involving Distinct Transcriptional Programs.

Decidual stromal cells differentiate from endometrial stromal fibroblasts (ESFs) under the influence of progesterone and cyclic adenosine monophosphate (cAMP) and are essential for implantation and the maintenance of pregnancy. They evolved in the stem lineage of placental (eutherian) mammals coincidental with the evolution of implantation. Here we use the well-established in vitro decidualization protocol to compare early (3 days) and late (8 days) gene transcription patterns in immortalized human ESF. We document extensive, dynamic changes in the early and late decidual cell transcriptomes. The data suggest the existence of an early signal transducer and activator of transcription (STAT) pathway dominated state and a later nuclear factor κB (NFKB) pathway regulated state. Transcription factor expression in both phases is characterized by putative or known progesterone receptor ( PGR) target genes, suggesting that both phases are under progesterone control. Decidualization leads to proliferative quiescence, which is reversible by progesterone withdrawal after 3 days but to a lesser extent after 8 days of decidualization. In contrast, progesterone withdrawal induces cell death at comparable levels after short or long exposure to progestins and cAMP. We conclude that decidualization is characterized by a biphasic gene expression dynamic that likely corresponds to different phases in the establishment of the fetal-maternal interface.

Fixation methods and implants in shoulder stabilization: A historical perspective

BackgroundTreatment for shoulder instability has changed significantly over the past decade from open procedures to arthroscopic procedures using a variety of different fixation methods and implants. The development of these implants has been highly influenced by the numerous complications that have arisen using early designs. MethodsA review of the literature was performed to describe the history of shoulder stabilization. ConclusionAs biomedical technology improves, we should continue to see changes to implant design and manufacturing. Having an understanding of the history and evolution of these implants will provide us with context in which to guide future implant design and clinical use. This review article provides a comprehensive overview of the evolution of early shoulder stabilization techniques and implants to the modern implants being used today.

CAD/CAM technology in implant abutment design

Study of implants has become indispensable and so is the biomechanics related to dental implant therapy. Implant therapy is a fast-growing and brightest prospect in the rehabilitation of completely and partially edentulous arches. The evolution of implants has become a ‘restorative driven ’field, and it is therefore important to know the designing principles of abutments and its connection to the implants and its rationale for use in clinical practice. The key is to have an optimum selection and designing of the implant to meet the implant position and angulations in the clinical scenario. Implant abutment connection is a crucial synapse between the implant and the abutment. It is an important determinant of the strength and stability of an implant supported restoration and plays a major role in the success of the implant. This article highlights designing principles of various abutments and its role in aesthetics and the application of computer-aided design and computer-aided manufacturing to produce implant abutment.

Preparation and evaluation of rotigotine-loaded implant for the treatment of Parkinson’s disease and its evolution study

PurposeTo develop rotigotine-loaded implants (RI) to achieve continuous release of rotigotine for long duration for the treatment of Parkinson’s disease (PD). MethodsRI was prepared by hot-melt extrusion method using poly (lactide-co-glycolide) (PLGA) as the matrix. In vitro drug release was optimized by drug loading, melting temperature during preparing process and additives. The surface and internal morphology of RI was imaged by SEM. The in vivo release profile of RI was investigated on rat. ResultsRI prepared with PLGA 7525 5A showed sustained release of 40days while suffering a lag phase, which was significantly shortened by blending 5050 2A and mannitol in the matrix. RI prepared by 7525 5A/5050 2A/mannitol=55:10:5 (rotigotine 30%) showed a 40-day sustained release in vivo with no lag phase. The drug release from RI was also affected by drug loading and melting temperature probably due to the drug state existed in the implant. The evolution of implants during release process was correlated well with the drug release kinetics. ConclusionRI could achieve sustained drug release for 40days which could supply an alternative of continuous dopaminergic stimulation (CDS) for the treatment of PD.

Le monachisme insulaire armoricain d'après les textes hagiographiques

The beginnings of monasticism are associated with deserts, especially those of Egypt and Syria, the withdrawal from the world allowing to seek God. This model also influenced the Martinian and Lerinian monasticism, and as we know, the Celtic monasticism. In this context has developed the concept of island desert : the island was a new kind of desert, whose shores became identified with the boundaries of the monastic enclosure. This notion of island desert is very present in Armorican Brittany, where the islands are numerous for this withdrawal. However, the oldest Breton saints’ lives, those of Guénolé, Paul Aurelian, Malo, Magloire and others, and the archaeological findings allow us to put this notion into perspective. It appears indeed that the islands occupied by the monks were concentrated in a few well-defined areas (Channel Islands, archipelago of Brehat, Brest roadstead, etc.), and represented links along the maritime routes. This paper aims therefore to study the Armorican island monastic settlements in their geographical, political and religious context and to study the nature of their insularity (re use of previous structures, evolution of implantation). We thus see that an island settlement did not necessarily imply the isolation and that the Armorican island monasticism was strongly connected to the mainland and its political and ecclesiastical structures.

Empfehlungen zur Sexualtität nach Hüfttotalprothesen-Implantation (Ein Kamasutra für Patienten nach Hüfttotalendoprothese?)

Population is getting older and arthroplasty is getting more common. And the evolution of implants and their better longevity enables arthroplasty to be done for younger patients too. Therefore sexual activity with hip prosthesis is more common. Literature demonstrates a positive effect of total hip arthroplasty for sexual activity. Despite the euphoria due to painfree movement of the joint, the risk of a luxation of prosthesis should not be underestimated. Especially during the first three months after surgery this risk is relatively high. This also makes sexual activity - not only in this time period, a potential risk for hip dislocation. We do recommend written guidelines for patients to be given to them preoperatively. This will allow some privacy.

Effects of implant diameter, drug loading and end-capping on praziquantel release from PCL implants

Praziquantel (PZQ)-loaded poly(ɛ-caprolactone) (PCL) cylindrical implants were fabricated and characterized. Implant diameter (3, 4 and 8 mm), drug loading (25% and 50%), and the end-capping were investigated to evaluate their effects on drug release. The evolution of implants with release time was conducted in terms of implant microstructure, crystallinity, drug content and molecular weight of PCL. The results showed that drug release was fastest for the implant with a diameter of 3 mm and slowest for the implant with a diameter of 8 mm; drug release from the implant with a drug content of 50% was faster than that from the implant with a drug content of 25%; the release of PZQ from the end-capped implants was slightly slower than that from the corresponding end-uncapped implants. The effect of drug loadings on PZQ release was related with diameter of the implants and the effect was weakened as diameter of the implants increased. The drug release data for all the implants were best fitted with Ritger–Peppas model, therefore Fickian diffusion was the predominant release mechanism. The evolution of implants with release time verified that PZQ was gradually released from the exterior to the interior of the implants.

The dynamic condylar screw in the management of subtrochanteric fractures: does judicious use of biological fixation enhance overall results?

Subtrochanteric fractures are fraught with certain anatomic, biologic and biomechanical challenges. Evolution of implants like the Gamma nail, fixed-angle nail plates, compression hip screws and dynamic hip screws with trochanteric stabilization plates underlines a persistent quest for a better implant. We studied the dynamic condylar screw DCS as an implant on a series of 30 consecutive patients with subtrochanteric fractures. Our purpose was to assess this implant as a panacea for subtrochanteric fractures. All cases of AO type A and B were anatomically fixed, whereas type C was biologically plated. The idea was to assess the applicability and adaptability of the DCS. Fractures in 29 cases united, with one patient suffering from an implant failure. There were 17 excellent, 5 good, 5 fair and 3 poor results. The DCS is a definite advance over previous methods of treatment; when combined with the utilization of biological fixation techniques for comminuted fractures, can be relied upon to treat all types of subtrochanteric fractures.