Cell-surface interactions of rat tooth germ cells on various biomaterials

This is the first study to explore the effect of biomaterial on tooth germ cell adhesion and proliferation in vitro. The purpose of this study is to evaluate the effects of cell-surface interactions of tooth germ cells on biomaterials with various surface hydrophilicities. The biomaterials used in this study included polyvinyl alcohol (PVA), poly(lactic-co-glycolic acid) (PLGA), poly(ethylene-co-vinyl alcohol; EVAL), and polyvinylidene fluoride (PVDF). Cell morphology was observed by photomicroscopy. Cell growth was assayed with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) reduction activity and the characteristic expression of amelogenin and collagen type I in tooth germ cells was investigated using immunocytochemistry. The results indicated that adhesion and proliferation of tooth germ cells to biomaterials with moderate hydrophilicity/hydrophobicity was superior compared to most hydrophobic material PVDF or mosthydrophilic material PVA in this study. Cellular adhesion and proliferation was evident on all tested biomaterials except PVA. The cell spheroids on PVA appeared not to be proliferated and remained as well as reattachable to tissue culture plates. In conclusion, biomaterials with moderate hydrophilicity are suitable for adhesion and proliferation of tooth germ cells. The material PVA may be a good biomaterial for maintaining tooth germ cells in three-dimensional biological restoration.     

Formation of salivary acinar cell spheroids in vitro above a polyvinyl alcohol-coated surface

Tissue engineering of salivary glands offers the potential for future use in the treatment of patients with salivary hypofunction. Biocompatible materials that promote acinar cell aggregation and function in vitro are an essential part of salivary gland tissue engineering. In this study, rat parotid acinar cells assembled into three-dimensional aggregates above the polyvinyl alcohol (PVA)-coated surface. These aggregates developed compact acinar cell spheroids resembling in vivo physiological condition, which were different from the traditional monolayered morphology in vitro. Cells remained viable and with better functional activity in response to acetylcholine in the spheroids and could form monolayered acinar cells when they were reinoculated on tissue culture polystyrene wells. To interpret the phenomenon further, we proposed that the formation of acinar cell spheroids on the PVA is mediated by a balance between two competing forces: the interactions of cell-PVA and cell-cell. This study demonstrated the formation of functional cell spheroids above a PVA-coated surface may provide an in vitro system for investigating cell behaviors for tissue engineering of artificial salivary gland.     

Polyvinylidene fluoride for proliferation and preservation of bovine corneal endothelial cells by enhancing type IV collagen production and deposition

In this study, biomaterials with different hydrophobic properties including polyvinyl alcohol (PVA), poly(ethylene-co-vinyl alcohol) (EVAL), tissue culture polystyrene (TCPS), and polyvinylidene fluoride (PVDF) were examined in the bovine corneal endothelial cells (BCECs) culture system to elucidate their possible impact on clinical demand and scientific interest. It was found that BCECs were inhibited to attach onto the PVA surface. Conversely, relatively more hydrophobic biomaterials EVAL, TCPS, and PVDF successfully initiate BCEC adhesion. Compared to EVAL, cultured BCECs on TCPS and PVDF exhibited higher viability. Furthermore, fibroblastic transformation on EVAL and TCPS was observed at day 17, but BCECs maintained typical hexagonal shape on the PVDF surface at day 21. This phenomenon can be rescued by previously coating type IV collagen on TCPS but not on EVAL. In addition, when BCECs were cultured on PVDF, the expressions of gap junction connexin-43, differentiation marker N-cadherin, and tight junction ZO-1 were well-developed, resembling the physiological phenotypes. After examining the type IV collagen expression by Western blot analysis and protein absorption test, a possible explanation for the better proliferation and preservation of BCECs on the PVDF substrate is that PVDF is a bioactive substratum which enables BCECs to synthesize and reserve more extracellular matrix type IV collagen, paving an important way to provide a more preferential environment for BCEC cultures. Accordingly, promoting CEC growth effects after cell-biomaterial association may be applied to the tissue engineering of corneal endothelium.     

The alteration of cell membrane charge after cultured on polymer membranes

In this work, cell electrophoresis, measuring the electrophoretic mobility of cells, was used to investigate the variation of surface charge property of cells after cultured on different polymer membranes. HepG2 cell line, derived from a well-differentiated, human hepatoma, was used as a model cell. The polymer biomaterials used in this study included polyvinyl alcohol (PVA), poly(ethylene-co-vinyl alcohol) (EVAL), and polyvinylidene fluoride (PVDF). For cells cultured in the presence of serum, cell mobility after being cultured on PVA substrates was considerably higher than that on EVAL or PVDF substrates. This effect was completely suppressed by cycloheximide (CHX) in the serum-free medium. Taken together, the cell surface charge property can be altered after cells cultured on different polymer substrates. The precise mechanism by which the variation of electrophoretic mobility of cultured cells is unknown, but it is reasonable to assume that the polymer substrates could influence the absorption of serum proteins on cell membrane surface to change cell electrophoretic mobility and, simultaneously, to regulate adhesion, growth and function of cultured cells.     

生物材料改性对人涎腺细胞生长的影响

目的：利用SO2等离子体对聚乳酸和聚醚酯膜进行表面改性，研究人类涎腺细胞系HSG细胞在生物材料上的生长。方法：材料的表面性质通过表面接触角和X射线光电子能谱(XPS)进行表征。细胞形态与生长情况则通过倒置显微镜观察和MTT检测来评估。结果：用SO2等离子体改性后，膜表面接枝上磺酸基团。亲水性明显增强；在几种材料中。用S02等离子体改性后的聚醚酯膜更适合HSG细胞的粘附生长。结论：用SO2等离子体改性后的聚醚酯材料可能用于人造涎腺的支架材料。     

Immobilization of L-Lysine on Microporous PVDF Membranes for Neuron Culture

Microporous poly(vinylidene fluoride) (PVDF) membranes with dense or porous surface were prepared by immersion precipitation of PVDF/TEP solutions in coagulation baths containing different amounts of water. Onto the membrane surface, poly(glycidyl methacrylate) (PGMA) was grafted by plasma-induced free radical polymerization. Then, L-lysine was covalently bonded to the as-grafted PGMA through ring-opening reactions between epoxide and amine to form amino alcohol. The highest attainable graft density of PGMA on a PVDF membrane was 0.293 mg/cm². This was obtained when the reaction was carried out on a porous surface under an optimized reaction condition. For immobilization of L-lysine, the yield was found to depend on the reaction temperature and L-lysine concentration. The maximal yield was 0.226 mg/cm², a value considerably higher than reported in the literature using other immobilization methods. Furthermore, neurons were cultured on L-lysine-immobilized PVDF membranes. The results indicated that these membrane surfaces were suited to the growth of neurons, with a MTT value higher than that of the standard culture dish.     

Human monocyte adhesion and activation on crystalline polymers with different morphology and wettability in vitro

This study evaluated the effects of crystalline polyamide (Nylon-66), poly(ethylene-co-vinyl alcohol) (PEVA), and poly(vinylidene fluoride) (PVDF) polymers with nonporous and porous morphologies on the ability of monocytes to adhere and subsequently activate to produce IL-1beta, IL-6, and tumor necrosis factor alpha. The results indicated monocyte adhesion and activation on a material might differ to a great extent, depending on the surface morphology and wettability. As the polymer wettability increases, the ability of monocytes to adhere increases but the ability to produce cytokines decreases. Similarly, these polymers, when prepared with porous surfaces, enhance monocyte adhesion but suppress monocyte release of cytokines. Therefore, the hydrophobic PVDF with a nonporous surface stimulates the most activity in adherent monocytes but shows the greatest inhibition of monocyte adhesion when compared with all of the other membranes. In contrast, the hydrophilic Nylon-66, which has a porous surface, is a relatively better substrate for this work. Therefore, monocyte behavior on a biomaterial may be influenced by a specific surface property. Based on this result, we propose that monocyte adhesion is regulated by a different mechanism than monocyte activation. Consequently, the generation of cytokines by monocytes is not proportional to the number of cells adherent to the surface.     

Surface modification of poly(vinylidenefluoride) to improve the osteoblast adhesion

Cell adhesion to biomaterials is mediated primarily by the interaction between surface bound proteins and corresponding receptors on the membrane of the cells. The attachment of fibronectin onto poly(vinylidenefluoride) (PVDF) surface and the application of PVDF as biomaterial in bone contact was the subject of our study. PVDF is a biomaterial established for soft tissue applications. Surface modifications of PVDF were performed by plasma induced graft copolymerisation of acrylic acid or CVD polymerisation of 4-amino[2.2]paracyclophane. The provided functionalised PVDF surface was used to immobilise fibronectin using different techniques. All modification steps were verified by means of X-ray photoelectron spectroscopy (XPS), attenuated total reflection infrared spectroscopy (IR-ATR) and contact angle measurements. Surface topology was studied by atomic force measurements (AFM). Protein adsorption was controlled by enzyme linked immunosorbent assay (ELISA). Cell attachment was enhanced if physically adsorbed fibronectin was used, while enhanced attachment and proliferation were induced by covalently binding fibronectin to the surface modified PVDF.     

Influence of the physical properties of two-dimensional polyester substrates on the growth of normal human urothelial and urinary smooth muscle cells in vitro

Although synthetic biomaterials have a wide range of promising applications in regenerative medicine and tissue engineering, there is limited insight into the basic materials properties that influence cellularisation events. The aim of this study was to investigate the influence of the physical properties of polyester films on the adherence and growth of normal human urothelial and urinary smooth muscle (SM) cells, as part of a programme for the development of potential biomaterials for bladder tissue engineering. Films of different thickness were produced by spin coating from solution. Cell attachment and proliferation were analysed and revealed a reproducible and significant growth advantage over the initial 7 days for both cell types on poly(lactide-co-glycolide) (PLGA) versus poly(epsilon-caprolactone) (PCL), and on thick versus thin films. In order to understand the basis of the variation in cell growth, the surface morphology, degradation behaviour and mechanical properties of the films were investigated. The pattern of cell attachment and growth was found to be unrelated to surface topography and no distinction in film degradation behaviour was found to account for differences in cell growth, except at late time points (14 days), where degradation of thin PLGA films became significant. By contrast, the flexural loss and storage moduli were found to be reduced in films composed of PLGA versus PCL, and also as film thickness increased, indicating that mechanical properties of biomaterials can influence cell growth. We conclude that elastic modulus is relevant to biology at the cellular scale and may also be influential at the tissue/organ level, and is a critical parameter to be considered during development of synthetic biomaterials for tissue engineering.     

MG63 osteoblastic cell adhesion to the hydrophobic surface precoated with recombinant osteopontin fragments

The hydrophobicity of biomaterials has been recognized as a limitation to the adequate function of anchorage-dependent cells when hydrophobic biomaterials are used for tissue engineering. This is due to flawed solid-state signals from cell adhesion. In this study, a recombinant osteopontin (rOPN17-169) fragment containing the cell adhesion motifs was expressed in E. coli and was precoated on the hydrophobic surface prior to osteoblastic MG63 cell culture. Precoating the hydrophobic surface with rOPN17-169 improved osteoblastic cell adhesion, which was blocked by soluble RGDS. The adhesion of MG63 cells to rOPN17-169 pre-coated surface-activated mitogen-activated protein kinases (MAPK) such as extracellular signal-receptor kinase 1/2, p38, and c-Jun N-terminal kinase (JNK). In addition, p38 MAPK was activated in response to a soluble factor of transforming growth factor-beta in the cells adhered to the hydrophobic surface via rOPN17-169. This suggests that rOPN17-169 precoated on the hydrophobic surface can allow osteoblastic cells to generate adhesion signals sufficient for cell adhesion, MAPK activation, and the cytokine activation of osteoblastic cells.     

Adsorbed serum albumin is permissive to macrophage attachment to perfluorocarbon polymer surfaces in culture

Monocyte/macrophage adhesion to biomaterials, correlated with foreign body response, occurs through protein-mediated surface interactions. Albumin-selective perfluorocarbon (FC) biomaterials are generally poorly cell-conducive because of insufficient receptor-mediated surface interactions, but macrophages bind to albumin-coated substrates and also preferentially to highly hydrophobic fluorinated surfaces. Bone marrow macrophages (BMMO) and IC-21, RAW 264.7, and J774A.1 monocyte/macrophage cells were cultured on FC surfaces. Protein deposition onto two distinct FC surfaces from complex and single-component solutions was tracked using fluorescence and time-of-flight secondary ion mass spectrometry (ToF-SIMS) methods. Cell adhesion and growth on protein pretreated substrates were compared by light microscopy. Flow cytometry and integrin-directed antibody receptor blocking were used to assess integrins critical for monocyte/macrophage adhesion in vitro. Albumin predominantly adsorbs onto both FC surfaces from 10% serum. In cultures preadsorbed with albumin or serum-dilutions, BMMO responded similar to IC-21 at early time points. Compared with Teflon AF, plasma-polymerized FC was less permissive to extended cell proliferation. The beta(2) integrins play major roles in macrophage adhesion to FC surfaces: antibody blocking significantly disrupted cell adhesion. Albumin-mediated cell adhesion mechanisms to FC surfaces could not be clarified. Primary BMMO and secondary IC-21 macrophages behave similarly on FC surfaces, regardless of preadsorbed protein biasing, with respect to adhesion, cell morphology, motility, and proliferation.     

Differentiation, growth and activity of rat bone marrow stromal cells on resorbable poly(L/DL-lactide) membranes

Nonporous and porous membranes produced from poly(L/DL-lactide) 80/20% were characterized using profilometry, contact-angle measurements, infra-red spectroscopy, X-ray photoemission spectroscopy and scanning electron microscopy, and used to culture bone marrow stromal cells isolated from the rat femora. The cells were cultured for 5, 10, 15 and 20 days. Cell growth and activity was estimated from the amounts of DNA, alkaline phosphatase activity and total protein amount present in the cell lysate and cell differentiation was assessed histochemically. Cell morphology was estimated from scanning electron microscopy. The cells fully expressed osteoblastic phenotype, revealed spindle-shaped, ellipsoidal morphology, developed podia, produced an abundant fibrillar extracellular matrix and mineral noduli. The number of cells on the membranes increased with time of culturing and was higher for the porous membranes than the nonporous membranes. Osteoblastic differentiation was most significant between 5 and 10 days of culture. The total amounts of DNA, alkaline phosphatase and proteins increased with time of culturing. The surface characteristics of the porous membranes were superior to the nonporous membranes.     

壳聚糖-明胶-果胶膜对骨髓基质干细胞的细胞行为研究

目的 考察壳聚糖-明胶-果胶膜对骨髓基质干细胞（MSC）的作用,为组织工程提供一种新的可望用于组织工程的生物材料. 方法 将MSC接种到壳聚糖-明胶-果胶（CS-Gel-P）膜和壳聚糖-明胶（CS-Gel）膜上,观察其生长形态,用MTT法测定其细胞活性,并考察其碱性磷酸酶活性表达. 结果 在CS-Gel-P膜上接种的MSC表现出比在CS-Gel膜和组织培养板（TCPS）上更好黏附性能,同时在不同时间点的碱性磷酸酶表达也均高于CS-Gel膜,在两种不同膜上的MSC的细胞活性差异无统计学意义. 结论 果胶的加入可以促进MSC的黏附和生长,同时更能促进MSC诱导分化为成骨细胞.     

Surface modification by complexes of vitronectin and growth factors for serum-free culture of human osteoblasts

Cell attachment, expansion, and migration in three-dimensional biomaterials are crucial steps for effective delivery of osteogenic cells into bone defects. Complexes composed of vitronectin (VN), insulin-like growth factors (IGFs), and insulin growth factor-binding proteins (IGFBPs) have been reported to enhance cell attachment, proliferation, and migration in a variety of cell lines in vitro. The aim of this study was to examine whether prebound complexes of VN and IGFs +/- IGFBPs could facilitate human osteoblast serum-free expansion in vitro and enhance cell attachment, proliferation, and migration in three-dimensional biomaterial constructs. Human osteoblasts derived from alveolar bone chips and the established human osteoblast cell line Saos-2 were used. These cells were seeded on tissue culture plates and porous scaffolds of type I collagen sponges and polyglycolic acid (PGA), which had been coated with VN +/- IGFBP-5 +/- IGF-I. Cell attachment, proliferation, and migration were evaluated by cell counting, confocal microscopy, and scanning electron microscopy. The number of attached human osteoblasts was significantly higher in VN-coated polystyrene culture dishes. Furthermore, significant increases in cell proliferation were observed when growth factors were bound to these surfaces in the presence of VN. In the two scaffold materials examined, greater cell attachment was found in type I collagen sponges compared with PGA scaffolds. However, coating the scaffolds with complexes composed of VN + IGF-I or VN + IGFBP-5 + IGF-I enhanced cell attachment on PGA. Moreover, the presence of VN + IGFBP-5 + IGF-I resulted in significantly greater osteoblast migration into deep pore areas as compared with untreated scaffolds or scaffolds treated with fetal calf serum. These results demonstrated that complexes of VN + IGFBP-5 + IGF-I can be used to expand osteoblasts in vitro under serum-free conditions and enhance the attachment and migration of human osteoblasts in three-dimensional culture. This in turn suggests a potential application in surface modification of biomaterials for tissue reconstruction.     

The biocompatibility of novel starch-based polymers and composites: in vitro studies

Studies with biodegradable starch-based polymers have recently demonstrated that these materials have a range of properties. which make them suitable for use in several biomedical applications, ranging from bone plates and screws to drug delivery carriers and tissue engineering scaffolds. The aim of this study was to screen the cytotoxicity and evaluate starch-based polymers and composites as potential biomaterials. The biocompatibility of two different blends of corn-starch, starch ethylene vinyl alcohol (SEVA-C) and starch cellulose acetate (SCA) and their respective composites with hydroxyapatite (HA) was assessed by cytotoxicity and cell adhesion tests. The MTT assay was performed with the extracts of the materials in order to evaluate the short-term effect of the degradation products. The cell morphology of L929 mouse fibroblast cell line was also analysed after direct contact with polymers and composites for different time periods and the number of cells adhered to the surface of the polymers was determined by quantification of the cytosolic lactate dehydrogenase (LDH) activity. Both types of starch-based polymers exhibit a cytocompatibility that might allow for their use as biomaterials. SEVA-C blends were found to be the less cytotoxic for the tested cell line, although cells adhere better to SCA surface. The cytotoxicity test also revealed that SCA and SEVA-C composites have a similar response to the one obtained for SCA polymer. Scanning electron microscopy (SEM) analysis showed that cells were much more spread on the SCA polymer and LDH measurements showed a higher number of cells on this surface.     

Designing a binding interface for control of cancer cell adhesion via 3D topography and metabolic oligosaccharide engineering

This study combines metabolic oligosaccharide engineering (MOE), a technology where the glycocalyx of living cells is endowed with chemical features not normally found in sugars, with custom-designed three-dimensional biomaterial substrates to enhance the adhesion of cancer cells and control their morphology and gene expression. Specifically, Ac(5)ManNTGc, a thiol-bearing analog of N-acetyl-d-mannosamine (ManNAc) was used to introduce thiolated sialic acids into the glycocalyx of human Jurkat T-lymphoma derived cells. In parallel 2D films and 3D electrospun nanofibrous scaffolds were prepared from polyethersulfone (PES) and (as controls) left unmodified or aminated. Alternately, the materials were malemided or gold-coated to provide bio-orthogonal binding partners for the thiol groups newly expressed on the cell surface. Cell attachment was modulated by both the topography of the substrate surface and by the chemical compatibility of the binding interface between the cell and the substrate; a substantial increase in binding for normally non-adhesive Jurkat line for 3D scaffold compared to 2D surfaces with an added degree of adhesion resulting from chemoselective binding to malemidede-derivatived or gold-coated surfaces. In addition, the morphology of the cells attached to the 3D scaffolds via MOE-mediated adhesion was dramatically altered and the expression of genes involved in cell adhesion changed in a time-dependent manner. This study showed that cell adhesion could be enhanced, gene expression modulated, and cell fate controlled by introducing the 3D topograhical cues into the growth substrate and by creating a glycoengineered binding interface where the chemistry of both the cell surface and biomaterials scaffold was controlled to facilitate a new mode of carbohydrate-mediated adhesion.     

许旺细胞在不同孔径丝素蛋白支架上的生长

背景：细胞在生物支架上的生长行为受到支架表面形貌、润湿性、孔径及孔隙率等多种因素影响。 目的：观察许旺细胞在不同孔径丝素蛋白支架上的生长情况。 方法：制备大孔径50~60 µm、小孔径10~   20 µm两种多孔丝素材料。选用许旺细胞永生化细胞R3 [33-10ras3]为种子细胞,当细胞在培养瓶底形成致密单层时即可消化细胞并进行接种实验,将许旺细胞悬液种于不同形貌的多孔丝素材料表面。复合培养1周后,扫描电镜观察许旺细胞的生长形态及增殖等情况。 结果与结论：不同孔径丝素材料的表面可见许旺细胞生长情况不一。在10~20 µm孔径材料支架上,细胞浓度较低,细胞表现为特异的双极性形态,细胞与细胞之间或平行排列,或首尾相连成细胞链;细胞与细胞之间或平行排列,或首尾相连成细胞链;在50~ 60 µm孔径丝素材料支架上,细胞浓度较高,细胞多为球形,单个分散在多孔支架表面,或呈现成团成串葡萄样聚集在孔的底部,未延展成双极性形态,只有极少量生长在孔与孔之间嵴上的细胞呈双极样。说明多孔丝素蛋白支架的孔径对许旺细胞的黏附、生长有一定的影响,许旺细胞更适合生长在孔径略大于胞体直径的支架材料上。     

In vitro growth and activity of primary chondrocytes on a resorbable polylactide three-dimensional scaffold

Sheep articular chondrocytes were cultured for 3, 6, and 9 weeks on a three-dimensional porous scaffold from poly(L/DL-lactide) 80/20%. Cell growth and activity was estimated from the amount of proteoglycans attached to the polylactide scaffold and the amounts of DNA and proteins measured in the cell lysate. Cell morphology was assessed from scanning electron microscopy. Histochemical staining of proteoglycans present in the sponge was used to visualize the chondrocyte ingrowth in the scaffold. The amounts of DNA, proteins, and proteoglycans increased with time of culturing. Chondrocytes on the polylactide scaffold maintained their round shape. The cell ingrowth into the sponge progressed with time of culturing and proceeded from the upper surface of the sponge toward its lower surface. At 9 weeks, the chondrocytes filled the whole scaffold and reached the opposite side of the sponge. The proteoglycans network was, however, more dense at the upper half of the scaffold.     

改性聚偏氟乙烯膜的生物相容性研究

目的通过测定改性聚偏氟乙烯（PVDF）的生物相容性,判断其应用于医用分离材料领域的可行性。方法分别用聚乙二醇（PEG）和聚吡咯烷酮（PVP）对PVDF共混改性,将PEG改性的PVDF称为PVDF1,将PVP改性的PVDF称为PVDF2。测定其亲水性、蛋白吸附性、细胞毒性、溶血率和动态凝血性,并与临床常用分离膜材料聚醚砜（PES）相比较。结果 PVDF材料的蛋白吸附性能优于PES;改性后的PVDF膜（PVDF1和PVDF2）的亲水性提高,接触角从86.5°下降为63.8°、65.7°左右。同时PVDF1、PVDF2对牛血清白蛋白的吸附也从58.6mg/m2下降为25.7mg/m2、38.5mg/m2;细胞毒性为一级,细胞增殖率〉80%;溶血率为分别为2.9%、2.4%,均小于5.0%,符合国标GB/T16886对材料溶血性的要求;改性PVDF的动态抗凝血性和体外细胞毒性比PES材料略好。结论改性PVDF具有良好的生物相容性,可以作为医用材料进一步研究。     

Development and characterisation of novel cross-linked bio-elastomeric materials

Recombinantly-engineered elastin-like polypeptides (ELPs) possess many of the favourable attributes of the native elastin protein, making them an attractive option for designing biomaterials for tissue-engineering applications. The focus of this study was to synthesize and characterise the bulk material properties of two ELP sequences, ELP2 and ELP4, cross-linked with lysine diisocyanate (LDI). The two distinct ELPs consist of repeating hydrophobic and hydrophilic cross-linking domains in a block co-polymer structure, however, differ by the number of respective domains. Depending on the conditions sets for the cross-linking reactions, two different ELP-based materials were synthesized: a gel-like relatively non-porous material and a porous foam-like material, from both ELP sequences. The physical material properties were characterised by scanning electron microscopy, compression testing, differential calorimetry analysis and swelling analysis. The bulk material properties were found to vary depending on the ELP sequence investigated. ELP gels were also found to have a more dense solidified morphology, lower compressive moduli, higher melting temperature and greater swelling capacity than the porous ELP foams. These novel cross-linked bio-elastomeric materials show promising properties for soft tissue replacement, particularly in load-bearing applications.