A novel self-gripping long-term resorbable mesh providing temporary support for open primary ventral and incisional hernia.

A novel synthetic fully long-term resorbable self-gripping mesh has been recently developed to reinforce soft tissue where weakness exists during ventral hernia repair open procedures. This resorbable mesh is a macroporous, knitted, poly-L-lactide, poly-trimethylene carbonate copolymer monofilament mesh with the ProGrip™ technology, providing grips on one side of the mesh. A new poly-L-lactide, poly-trimethylene copolymer was developed to provide the required features for mechanical support during at least 20 weeks covering the critical healing period, including resistance to fatigue under cyclic loading conditions, as it occurs in patients. The yarns and mesh initial physical and biomechanical properties were characterized. Then, the mesh mechanical strength was evaluated over time. The mechanical properties of the proposed mesh were found to be above the generally recognized threshold value to mechanically support the repair site of a hernia over a 20-week period during in-vitro cyclic loading test. The mesh performance was evaluated in vivo using a published preclinical porcine model of hernia repair at 4-, 12- and 20-weeks post implantation. The burst strength of the hernia repair sites reinforced with the new mesh were higher at 4 & 12 weeks and comparable at 20 weeks to the one of the native abdominal walls. At all time points, the mesh was well tolerated with moderate inflammation and was fast integrated in the abdominal wall at 4 weeks. Particularly, the grips were nicely engulfed in the newly formed connective tissue. They must facilitate the anchoring of the mesh by their extension from the mesh and their mushroom shape. The preclinical data of the self-gripping resorbable mesh suggests that it has all the favorable characteristics for future clinical use during ventral hernia repair open procedures.

Incidence and risk factors for incisional hernia and recurrence: Retrospective analysis of the French national database.

AIM: The aim of this work was to determine the rate of incisional hernia (IH) repair and risk factors for IH repair after laparotomy. METHOD: This population-based study used data extracted from the French Programme de Médicalisation des Systèmes d'Informations (PMSI) database. All patients who had undergone a laparotomy in 2010, their hospital visits from 2010 to 2015 and patients who underwent a first IH repair in 2013 were included. Previously identified risk factors included age, gender, high blood pressure (HBP), obesity, diabetes and chronic obstructive pulmonary disease (COPD). RESULTS: Among the 431 619 patients who underwent a laparotomy in 2010, 5% underwent IH repair between 2010 and 2015. A high-risk list of the most frequent surgical procedures (>100) with a significant risk of IH repair (>10% at 5 years) was established and included 71 863 patients (17%; 65 procedures). The overall IH repair rate from this list was 17%. Gastrointestinal (GI) surgery represented 89% of procedures, with the majority of patients (72%) undergoing lower GI tract surgery. The IH repair rate was 56% at 1 year and 79% at 2 years. Risk factors for IH repair included obesity (31% vs 15% without obesity, p  < 0.001), COPD (20% vs 16% without COPD), HBP (19% vs 15% without HBP) and diabetes (19% vs 16% without diabetes). Obesity was the main risk factor for recurrence after IH repair (19% vs 13%, p < 0.001). CONCLUSION: From the PMSI database, the real rate of IH repair after laparotomy was 5%, increasing to 17% after digestive surgery. Obesity was the main risk factor, with an IH repair rate of 31% after digestive surgery. Because of the important medico-economic consequences, prevention of IH after laparotomy in high-risk patients should be considered.

Cellular and collagen reference values of gingival and periodontal ligament tissues in rats: a pilot study.

Reference data are lacking on the periodontal ligament and the gingival tissue of the rat model, which would be useful for studies of new medical or biomaterial periodontal treatments. The objective of the current study was to propose cellular and collagen reference values of gingival and periodontal ligament tissues in rat, using a simple and reliable quantitative method after decalcification. Mandibular samples of ten adult Sprague-Dawley rats were used. Mild decalcification was carried out using ethylenediaminetetraacetic acid (EDTA) to preserve the morphology of tissues. Half of the samples were decalcified and the other half were not. The gingiva and the periodontal ligament were analyzed. Descriptive histology and computer-assisted image analysis were performed. The data showed that qualitatively, cellular and extracellular matrix morphologies were well preserved compared to non-decalcified periodontal soft tissue biopsies. Histomorphometrically, constitutive cellularity and the total amount of native collagen, collagen directionality and collagen anisotropy in both experimental conditions did not significantly differ. Taken together, these results suggested that EDTA decalcification did not negatively affect the studied endpoints. Moreover, this mild decalcification method allowed in situ maintenance of the periodontal soft and hard tissue integrity. The structural and compositional computerized assessment performed in the healthy periodontal soft tissue could provide reference values that will be required for future assessment on the effects of pathological, reparative and regenerative processes in rat periodontal soft tissues.

Resorbable Synthetic Meshes for Abdominal Wall Defects in Preclinical Setting: A Literature Review.

BACKGROUND: Prosthetic materials for the repair of abdominal wall defects have been studied extensively to improve outcome. A new approach can be the use of a slowly resorbable synthetic mesh, which aims to combine advantages of both synthetic and biological meshes. The objective of this review is to give an overview of the physicochemical characteristics and biomechanical, histological, and macroscopic outcome (recurrence, adhesion formation) of the use of resorbable synthetic meshes, for treatment and prevention of abdominal wall hernias, based on experimental studies. METHODS: A systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Only experimental studies were included. Outcome parameters were resorption, degradation, organization of connective tissue, inflammatory response, tensile strength, and amount of adhesion formation. Surgical characteristics were taken into account as well (type of defect, clean versus contaminated model, position mesh, repair of the defect, recurrences). RESULTS: In total, eleven articles were included. Three absorbable synthetic meshes are currently available: GORE BIO-A mesh (Gore), TIGR Matrix Surgical mesh (Novus Scientific), and Phasix mesh (Bard). Two studies concluded that, despite an early transient inflammatory reaction in the first months, remodeling was good in GORE BIO-A, 6-12 mo after augmentation or suture line reinforcement with only minimal to moderate adhesions when used intraperitoneally. The TIGR Matrix Surgical mesh shows only partial remodeling with a persistent foreign body reaction after 1 y. Phasix mesh seems to perform well in extraperitoneal implantation after 1 y in two studies, although the defect was small. Only two studies directly compared two resorbable synthetic meshes under the same circumstances. The latter also included a number of animals where the meshes were used in a contaminated nonhernia model. No hernia recurrences or deaths of animals were described in all studies. CONCLUSIONS: The use of resorbable synthetic meshes in the prevention or treatment of abdominal wall defects in animal experiments with small defects in clean setting seems safe, with no serious complications related to the device during short-term follow-up. However, there is no evidence available that can support the advantages of resorbable synthetic meshes over the use of synthetic or biological meshes, mostly due to lack of good data. More experimental studies are needed, followed by randomized controlled trials and prospective registries in humans with a sufficiently long follow-up period, to reveal the potential advantages in clinical practice.

Translational Research Symposium-collaborative efforts as driving forces of healthcare innovation.

The 5th Translational Research Symposium was organised at the annual meeting of the European Society for Biomaterials 2018, Maastricht, the Netherlands, with emphasis on the future of emerging and smart technologies for healthcare in Europe. Invited speakers from academia and industry highlighted the vision and expectations of healthcare in Europe beyond 2020 and the perspectives of innovation stakeholders, such as small and medium enterprises, large companies and Universities. The aim of the present article is to summarise and explain the main statements made during the symposium, with particular attention on the need to identify unmet clinical needs and their efficient translation into healthcare solutions through active collaborations between all the participants involved in the value chain.

Joint academic and industrial efforts towards innovative and efficient solutions for clinical needs.

The 4th Translational Research Symposium (TRS) was organised at the annual meeting of the European Society for Biomaterials (ESB) 2017, Athens, Greece, with a focus on 'Academia-Industry Clusters of Research for Innovation Catalysis'. Collaborations between research institutes and industry can be sustained in several ways such as: European Union (EU) funded consortiums; syndicates of academic institutes, clinicians and industries; funding from national governments; and private collaborations between universities and companies. Invited speakers from industry and research institutions presented examples of these collaborations in the translation of research ideas or concepts into marketable products. The aim of the present article is to summarize the key messages conveyed during these lectures. In particular, emphasis is put on the challenges to appropriately identify and select unmet clinical needs and their translation by ultimately implementing innovative and efficient solutions achieved through joint academic and industrial efforts.

FTIR microscopy contribution for comprehension of degradation mechanisms in PLA-based implantable medical devices.

The integration and evolution of implantable medical devices made of bioresorbable polymers and used for temporary biomedical applications are crucial criteria in the success of a therapy and means of follow-up after implantation are needed. The objective of this work is to develop and evaluate a method based on microscopic Fourier Transform InfraRed spectroscopy (FTIR) mappings to monitor the degradation of such polymers on tissue explant sections, after implantation. This technique provided information on their location and on both their composition and crystallinity, which is directly linked to their state of degradation induced predominantly by chain scissions. An in vitro study was first performed on poly(L-lactic acid) (PLLA) meshes to validate the procedure and the assumption that changes observed on FTIR spectra are indeed a consequence of degradation. Then, mappings of in vivo degraded PLLA meshes were realized to follow up their degradation and to better visualize their degradation mechanisms. This work further warrants its translation to medical implants made of copolymers of lactic acid and to other polyesters.

Comparing the host tissue response and peritoneal behavior of composite meshes used for ventral hernia repair.

BACKGROUND: The use of a prosthetic material is the best treatment option for ventral hernia repair; one of the most frequently performed abdominal surgery procedures. This preclinical study compares the behavior of a new mesh (Parietex composite ventral patch [Ptx]) with that of two existing meshes used for ventral hernia repair. MATERIALS AND METHODS: Fifty-four New Zealand White rabbits (3000 g) were used in an experimental model of umbilical hernia repair (diameter 1.5 cm). The materials tested were: Ventralex ST hernia patch (Vent) (Bard Davol Inc, Warwick, RI) (n = 18); Proceed ventral patch (Ethicon, Somerville, NJ) (PVP) (n = 18) and Ptx (Covidien, Sofradim, Trevoux, France) (n = 18). At 3, 7, 14 d, and 6 wk after implant, peritoneal behavior and adhesion formation were assessed by sequential laparoscopy. Mesh mesothelial cover was determined by scanning electron microscopy. Host tissue ingrowth (collagens I and III) and the macrophage response were assessed by immunohistochemical labeling. Animals were euthanized at 2, 6 wk, and 6 mo after surgery. Data were compared using the Mann-Whitney U test. RESULTS: Adhesion formation from 3 d-6 wk was significantly greater (P < 0.05) for PVP compared with Vent or Ptx. Three encapsulated PVP implants showed "tissue-integrated" adhesions affecting the intestinal loops. All three implant types showed similar patterns of collagen l and III deposition. The PVP mesh elicited the greater macrophage response both at 2 wk and 6 mo. CONCLUSIONS: Ptx and Vent showed excellent mesothelialization, which led to minimum adhesion formation. The appropriate tissue integration of Ptx in the parietal neoperitoneum is likely attributable to its deployment system.

Marine origin collagens and its potential applications.

Collagens are the most abundant high molecular weight proteins in both invertebrate and vertebrate organisms, including mammals, and possess mainly a structural role, existing different types according with their specific organization in distinct tissues. From this, they have been elected as one of the key biological materials in tissue regeneration approaches. Also, industry is constantly searching for new natural sources of collagen and upgraded methodologies for their production. The most common sources are from bovine and porcine origin, but other ways are making their route, such as recombinant production, but also extraction from marine organisms like fish. Different organisms have been proposed and explored for collagen extraction, allowing the sustainable production of different types of collagens, with properties depending on the kind of organism (and their natural environment) and extraction methodology. Such variety of collagen properties has been further investigated in different ways to render a wide range of applications. The present review aims to shed some light on the contribution of marine collagens for the scientific and technological development of this sector, stressing the opportunities and challenges that they are and most probably will be facing to assume a role as an alternative source for industrial exploitation.

Translating Ideas into Commercial Biomaterial Devices: A Path to Improving Healthcare.

The medical device industry is undergoing substantial transformations, looking to face the increasing pressures on healthcare systems and fundamental shifts in healthcare delivery. There is an ever-growing emphasis on identifying underserved clinical requirements and enhancing industry-academia partnerships to accelerate innovative solutions. In this context, an analysis of the requirements for translation, highlighting support and funding for innovation to transform an idea for a biomaterial device into a commercially available product, is discussed.

Development of three-layer collagen scaffolds to spatially direct tissue-specific cell differentiation for enthesis repair.

Enthesis repair remains a challenging clinical indication. Herein, a three-layer scaffold composed of a tendon-like layer of collagen type I, a fibrocartilage-like layer of collagen type II and a bone-like layer of collagen type I and hydroxyapatite, was designed to recapitulate the matrix composition of the enthesis. To aid tenogenic and fibrochondrogenic differentiation, bioactive molecules were loaded in the tendon-like layer or the fibrocartilage-like layer and their effect was assessed in in vitro setting using human bone marrow derived mesenchymal stromal cells and in an ex vivo model. Seeded human bone marrow mesenchymal stromal cells infiltrated and homogeneously spread throughout the scaffold. As a response to the composition of the scaffold, cells differentiated in a localised manner towards the osteogenic lineage and, in combination with differentiation medium, towards the fibrocartilage lineage. Whilst functionalisation of the tendon-like layer did not improve tenogenic cell commitment within the time frame of this work, relevant fibrochondrogenic markers were detected in the fibrocartilage-like layer when scaffolds were functionalised with bone morphogenetic protein 2 or non-functionalised at all, in vitro and ex vivo, respectively. Altogether, our data advocate the use of compartmentalised scaffolds for the repair and regeneration of interfacial tissues, such as enthesis.

Reactive oxygen species (ROS)--a family of fate deciding molecules pivotal in constructive inflammation and wound healing.

Wound healing requires a fine balance between the positive and deleterious effects of reactive oxygen species (ROS); a group of extremely potent molecules, rate limiting in successful tissue regeneration. A balanced ROS response will debride and disinfect a tissue and stimulate healthy tissue turnover; suppressed ROS will result in infection and an elevation in ROS will destroy otherwise healthy stromal tissue. Understanding and anticipating the ROS niche within a tissue will greatly enhance the potential to exogenously augment and manipulate healing. Tissue engineering solutions to augment successful healing and remodelling of wounded or diseased tissue rely on a controlled balance between the constructive and destructive capacity of the leukocyte secretome, including ROS. This review comprehensively considers leukocyte derived ROS in tissue repair with particular interest in surgical intervention with inclusion of a biomaterial. The article considers ROS fundamental chemistry, formation, stimulation and clearance before applying this to discuss the implications of ROS in healing tissue with and without a biomaterial. We also systematically discuss ROS in leukocyte signalling and compare and contrast experimental means of measuring ROS.

Development of a Connected Sensor System in Colorectal Surgery: User-Centered Design Case Study.

BACKGROUND: A successful innovative medical device is not only technically challenging to develop but must also be readily usable to be integrated into health care professionals' daily practice. Through a user-centered design (UCD) approach, usability can be improved. However, this type of approach is not widely implemented from the early stages of medical device development. OBJECTIVE: The case study presented here shows how UCD may be applied at the very early stage of the design of a disruptive medical device used in a complex hospital environment, while no functional device is available yet. The device under study is a connected sensor system to detect colorectal anastomotic leakage, the most detrimental complication following colorectal surgery, which has a high medical cost. We also aimed to provide usability guidelines for the initial design of other innovative medical devices. METHODS: UCD was implemented by actively involving health care professionals and all the industrial partners of the project. The methodology was conducted in 2 European hospitals: Grenoble-Alpes University Hospital (France) and Erasmus Medical Center Rotterdam (the Netherlands). A total of 6 elective colorectal procedures and 5 ward shifts were observed. In total, 4 workshops were conducted with project partners and clinicians. A formative evaluation was performed based on 5 usability tests using nonfunctional prototype systems. The case study was completed within 12 months. RESULTS: Functional specifications were defined for the various components of the medical device: device weight, size, design, device attachment, and display module. These specifications consider the future integration of the medical device into current clinical practice (for use in an operating room and patient follow-up inside the hospital) and interactions between surgeons, nurses, nurse assistants, and patients. By avoiding irrelevant technical development, this approach helps to promote cost-effective design. CONCLUSIONS: This paper presents the successful deployment over 12 months of a UCD methodology for the design of an innovative medical device during its early development phase. To help in reusing this methodology to design other innovative medical devices, we suggested best practices based on this case.

Assessing the combined effect of surface topography and substrate rigidity in human bone marrow stem cell cultures.

The combined effect of surface topography and substrate rigidity in stem cell cultures is still under-investigated, especially when biodegradable polymers are used. Herein, we assessed human bone marrow stem cell response on aliphatic polyester substrates as a function of anisotropic grooved topography and rigidity (7 and 12 kPa). Planar tissue culture plastic (TCP, 3 GPa) and aliphatic polyester substrates were used as controls. Cell morphology analysis revealed that grooved substrates caused nuclei orientation/alignment in the direction of the grooves. After 21 days in osteogenic and chondrogenic media, the 3 GPa TCP and the grooved 12 kPa substrate induced significantly higher calcium deposition and alkaline phosphatase (ALP) activity and glycosaminoglycan (GAG) deposition, respectively, than the other groups. After 14 days in tenogenic media, the 3 GPa TCP upregulated four and downregulated four genes; the planar 7 kPa substrate upregulated seven genes and downregulated one gene; and the grooved 12 kPa substrate upregulated seven genes and downregulated one gene. After 21 days in adipogenic media, the softest (7 kPa) substrates induced significantly higher oil droplet deposition than the other substrates and the grooved substrate induced significantly higher droplet deposition than the planar. Our data pave the way for more rational design of bioinspired constructs.

Monocyte response after colorectal surgery: A prospective cohort study.

Background: Tumor resection is the common approach in patients with colorectal malignancy. Profound insight into inflammatory changes that accompany the normal post-operative stress response will establish reference parameters useful for identification of putative complications. Alterations in circulating monocytes might be indicative as these cells are considered to be the most responsive leukocytes to trauma. Therefore, the aim of this study is to assess the monocyte subset kinetic and phenotypic changes in response to surgery. Methods: Fifty patients undergoing colorectal tumor resection were included in a multicenter prospective cohort study. Blood samples were collected early in the morning prior to surgery and the next days through postoperative day three for flowcytometric analysis. Leukocyte subtypes were identified and expression of activation stage-related markers by monocyte subsets was quantified. Results: Changes in leukocyte subset composition and monocyte subset phenotypes were most prominent at the first day postoperatively, after which these parameters typically returned to normal or near-normal preoperative values. The immunophenotypic alterations after surgery were most notable in classical and intermediate monocytes. These included up-regulation of activation markers CD64 and CD62L, but down-regulation of HLA-DR and CD54. Markers of de-activation, CD163 and CD206, were consistently increasingly expressed. Discussion/conclusion: The current study gives detailed insight into the peripheral blood leukocyte response after colorectal cancer surgery. This form of short-term stress induces a rapid and significant redistribution of immune cells. Immunophenotypic alterations in monocytes as a response to surgery suggest a mixed profile of cellular activation and de-activation.

Polysaccharide-based adhesive for biomedical applications: correlation between rheological behavior and adhesion.

Adhesion to biological tissues is a challenge especially when the adhesive is in contact with physiological fluids. Abdominal hernia is a disease that often requires the implantation of a mesh within the abdominal wall. To minimize pain and postsurgical complications, gluing the mesh appears to be a convenient method. For this purpose, a bioadhesive system based on solutions of chitosan and modified starch (oxidized maltodextrin) has been developed. Mixtures of these polysaccharides form either viscoelastic solutions or hydrogels, depending on various experimental parameters (chitosan concentration, starch degree of oxidation, molar ratio between amine and aldehyde functions, pH, etc.). An adhesion test was developed to assess the adherence of such systems under conditions similar to the intended use. The rheological behavior of each formulation was correlated to its adherence, and it was found that optimum adhesion is obtained for systems exhibiting an intermediate behavior between the viscoelastic solution and the gel.

Enabling MedTech Translation in Academia: Redefining Value Proposition with Updated Regulations.

Academic institutions are becoming more focused on translating new technologies for clinical applications. A transition from "bench to bedside" is often described to take basic research concepts and methods to develop a therapeutic or diagnostic solution with proven evidence of efficacy at the clinical level while also fulfilling regulatory requirements. The regulatory environment is evolving in Europe with transition and grace periods for the full enforcement of the Medical Device Regulation 2017/745 (MDR), replacing the Medical Device Directive 93/42/EEC (MDD). These new guidelines increase demands for scientific, technical, and clinical data with reduced capacity in regulatory bodies creating uncertainty in future product certification. Academic translational activities will be uniquely affected by this new legislation. The barriers and threats to successful translation in academia can be overcome by strong clinical partnerships, close-industrial collaborations, and entrepreneurial programs, enabling continued product development to overcome regulatory hurdles, reassuring their foothold of medical device development.

Development and characterisation of cytocompatible polyester substrates with tunable mechanical properties and degradation rate.

Although it has been repeatedly indicated the importance to develop implantable devices and cell culture substrates with tissue-specific rigidity, current commercially available products, in particular cell culture substrates, have rigidity values well above most tissues in the body. Herein, six resorbable polyester films were fabricated using compression moulding with a thermal presser into films with tailored stiffness by appropriately selecting the ratio of their building up monomers (e.g. lactide, glycolide, trimethylene carbonate, dioxanone, ε-caprolactone). Typical NMR and FTIR spectra were obtained, suggesting that the fabrication process did not have a negative effect on the conformation of the polymers. Surface roughness analysis revealed no apparent differences between the films as a function of polymer composition. Subject to polymer composition, polymeric films were obtained with glass transition temperatures from -52 °C to 61 °C; contact angles in water from 81 ° to 94 °; storage modulus from 108 MPa to 2,756 MPa and loss modulus from 8 MPa to 507 MPa (both in wet state, at 1 Hz frequency and at 37 °C); ultimate tensile strength from 8 MPa to 62 MPa, toughness from 23 MJ/m3 to 287 MJ/m3, strain at break from 3 % to 278 %, macro-scale Young's modulus from 110 MPa to 2,184 MPa (all in wet state); and nano-scale Young's modulus from 6 kPa to 15,019 kPa (in wet state). With respect to in vitro degradation in phosphate buffered saline at 37 °C, some polymeric films [e.g. poly(glycolide-lactide) 30 / 70] started degrading from day 7 (shortest timepoint assessed), whilst others [e.g. poly(glycolide-co-ε-caprolactone) 10 / 90] were more resilient to degradation up to day 21 (longest timepoint assessed). In vitro biological analysis using human dermal fibroblasts and a human monocyte cell line (THP-1) showed the potential of the polymeric films to support cell growth and controlled immune response. Evidently, the selected polymers exhibited properties suitable for a range of clinical indications.

Polysaccharide gels based on chitosan and modified starch: structural characterization and linear viscoelastic behavior.

We investigated the properties of polymeric systems formed by cross-linking chitosan with modified starch (oxidized maltodextrin). Such a macromolecular cross-linker proved to be efficient to react with chitosan with potentially minimal toxicity. The structural characterization of modified starch alone and of the two-polysaccharide reactive systems was performed using (1)H NMR and FTIR. The rheological behaviors of all systems, from solutions to gels, were also characterized. Depending on experimental parameters, such as chitosan concentration, cross-linking pH, degree of oxidation of starch, and molar ratio of reactive groups, different kinds of systems ranging from pure viscoelastic solutions to stiff hydrogels were formed. These versatile systems could be used in biomedical applications because of the good biocompatibility of their constituents.

The effect of aligned electrospun fibers and macromolecular crowding in tenocyte culture.

Tendon injuries continuously rise, and regeneration is not only slow, but also limited due to the poor endogenous healing ability of the tendon tissue. Tissue grafts constitute the clinical gold standard treatment for severe injuries, but inherent limitations drive the field toward tissue engineering approaches to create suitable tissue constructs. Recapitulation of the native microenvironment represent a key challenge for the development of tendon tissue equivalents in vitro that can be further utilized as implantable devices. Methods to maintain cellular phenotype and to enhance extracellular matrix deposition for accelerated development of tissue-like modulus should be developed. Herein, we assessed the combining effect of surface topography and macromolecular crowding in human tenocyte culture. Our data demonstrated that bidirectionally aligned electrospun fibers induce physiological cell growth, while macromolecular crowding enhanced and accelerated tissue-specific extracellular matrix deposition. Collectively, these data advocate the use of multifactorial approaches for the accelerated development of functional tissue-like surrogates in vitro.