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Surface coatings prepared by layer-by-layer technique permit loading of growth factors (GFs) and their spatially controlled release. Here, native chondroitin sulfate (nCS), oxidized CS (oCS100), or mixture of both (oCS50) are combined with collagen I (Col I) to fabricate polyelectrolyte multilayers (PEMs) that exhibit structural, mechanical, and biochemical cues like the natural extracellular-matrix. The use of oCS enables intrinsic cross-linking of PEM that offers higher stability, stiffness, and better control of bone morphogenetic protein-2 (BMP-2) release compared to nCS. oCS100 PEMs have enhanced stiffness, promote Col I fibrillization, and present BMP-2 in a matrix-bound manner. oCS50 PEMs show intermediate effects on osteogenesis, soft surface, high water content but also moderately slow BMP-2 release profile. C2C12 myoblasts used for osteogenesis studies show that oCS PEMs are more stable and superior to nCS PEMs in supporting cell adhesion and spreading as well as in presenting BMP-2 to the cells. oCS PEMs are triggering more osteogenesis as proved by the quantitative real-time polymerase chain reaction, immune and histochemical staining. These findings show that intrinsic cross-linking in oCS/Col I multilayers provides a successful tool to control GFs delivery and subsequent cell differentiation which opens new opportunities in regenerative therapies of bone and other tissues.

BBA advances 2, 100039 (2022). doi:10.1016/j.bbadva.2021.100039, The stratum corneum (SC) is the largest physical barrier of the human body. It protects against physical, chemicaland biological damages, and avoids evaporation of water from the deepest skin layers. For its correct functioning,the homeostasis of the SC lipid matrix is fundamental. An alteration of the lipid matrix composition and inparticular of its ceramide (CER) fraction can lead to the development of pathologies such as atopic dermatitis andpsoriasis. Different studies showed that the direct replenishment of SC lipids on damaged skin had positive effectson the recovery of its barrier properties.In this work, cerosomes, i.e. liposomes composed of SC lipids, have been successfully prepared in order toinvestigate the mechanism of interaction with a model SC lipid matrix. The cerosomes contain CER[NP], D-CER[AP], stearic acid and cholesterol. In addition, hydrogenated soybean phospholipids have been added to one ofthe formulations leading to an increased stability at neutral pH. For the mode of action studies, monolayermodels at the air-water interface and on solid support have been deployed. The results indicated that a stronginteraction occurred between SC monolayers and the cerosomes. Since both systems were negatively charged, thedriving force for the interaction must be based on the ability of CERs head groups to establish intermolecularhydrogen bonding networks that energetically prevailed against the electrostatic repulsion. This work proved forthe first time the mode of action by which cerosomes exploit their function as skin barrier repairing agents on theSC., Published by Elsevier, [Amsterdam]

The sensory end-organs responsible for hearing and balance in the mammalian inner ear are connected via a small membranous duct known as the ductus reuniens (also known as the reuniting duct (DR)). The DR serves as a vital nexus linking the hearing and balance systems by providing the only endolymphatic connection between the cochlea and vestibular labyrinth. Recent studies have hypothesized new roles of the DR in inner ear function and disease, but a lack of knowledge regarding its 3D morphology and spatial configuration precludes testing of such hypotheses. We reconstructed the 3D morphology of the DR and surrounding anatomy using osmium tetroxide micro-computed tomography and digital visualizations of three human inner ear specimens. This provides a detailed, quantitative description of the DR’s morphology, spatial relationships to surrounding structures, and an estimation of its orientation relative to head position. Univariate measurements of the DR, inner ear, and cranial planes were taken using the software packages 3D Slicer and Zbrush. The DR forms a narrow, curved, flattened tube varying in lumen size, shape, and wall thickness, with its middle third being the narrowest. The DR runs in a shallow bony sulcus superior to the osseus spiral lamina and adjacent to a ridge of bone that we term the “crista reuniens” oriented posteromedially within the cranium. The DR’s morphology and structural configuration relative to surrounding anatomy has important implications for understanding aspects of inner ear function and disease, particularly after surgical alteration of the labyrinth and potential causative factors for Ménière’s disease.

NanoImpact : an international journal of nanosafety research 19, 100239 (2020). doi:10.1016/j.impact.2020.100239, Published by Elsevier, Amsterdam

Objectives: Collagen membranes are not limited to be occlusive barriers as they actively support bone regeneration. However, the impact of bone-derived growth factors on their osteoconductive competence has not been examined. Methods: Twenty adult Sprague Dawley rats were included in the study. Calvaria defects with a diameter of five millimeter were created. The defect was covered with one layer of a collagen membrane previously soaked in conditioned medium of porcine bone chips or in culture medium alone. After 4Â weeks, microcomputed tomography was performed. Undecalcified thin-ground sections were subjected to light and scanning electron microscopy. Primary outcome parameter was the bone volume in the defect. Unit of analysis was the bone-conditioned medium (BCM). Results: In the central defect area of the control and the BCM group, median new bone connected to the host bone was 0.54 and 0.32 mm³, respectively (p = .10). In the ectocranial defect area, the control group showed significantly more bone than the BCM group (0.90 and 0.26 mm³; p = .02). Based on an exploratory interpretation, the control group had smaller bony islands than the BCM group. Scanning electron microscopy and histology indicate the formation of bone but also the collagen membrane to be mineralized in the defect site. Conclusions: These results demonstrate that the commercial collagen membrane holds an osteoconductive competence in a rat calvaria defect model. Soaking collagen membranes with BCM shifts bone formation toward the formation of bony islands rather than new bone connected to the host bone.