Bioresorbable Poly Research Articles

Enhancing the degradation properties of poly (trimethylene carbonate) by simple and effective copolymerization of trimethylene carbonate with p-dioxanone

Biodegradable polymeric materials play an important role in the field of clinical science. However, the advancement of non-toxic polymeric materials with excellent performance and controlled degradation properties remains a challenge. Herein, a series of biodegradable and bioresorbable poly (trimethylene carbonate-co-p-dioxanone) [P(TMC-co-PDO), PTD] copolymers were prepared as polymer materials through random copolymerization of trimethylene carbonate (TMC) and p-dioxanone (PDO). In vitro enzymatic degradation mediated by aspergillus oryzae lipase showed that PTD polymer materials exhibit a controllable degradation rate and well form-stability by regulating the PDO content in the composition. The relationship between the chemical structure and the final performance of the PTD copolymers at the molecular level was studied in detail. The results indicate that the introduction of PDO significantly enhances the form-stability of low molecular weight PTMC and significantly accelerates its degradation rate. This initiative provides a feasible strategy for the modification and extensive application of low molecular weight PTMC. It is envisioned that this PTD is a promising candidate for clinical polymer implantable drug delivery systems.

Using Laponite to Deliver BMP‐2 for Bone Tissue Engineering – In Vitro, Chorioallantoic Membrane Assay and Murine Subcutaneous Model Validation

AbstractFracture non‐union occurs due to various factors, leading to the development of potentially substantial bone defects. While autograft and allograft are the current gold standards for non‐union fractures, challenges related to availability and immune rejection highlight the need for improved treatments. A strategy in bone tissue engineering is to harness growth factors to induce an effect on cells to change their phenotype, behavior and initiate signaling pathways which lead to increased matrix deposition and tissue formation. Bone morphogenetic protein‐2 (BMP‐2) is a potent osteogenic growth factor however, given its rapid clearance time in vivo, there is a specific therapeutic window for efficacy while avoiding potential deleterious side‐effects. It is demonstrated that a Laponite nanoclay coating on a 3D printable and bioresorbable poly(caprolactone) trimethacrylate‐based resin enables binding of BMP‐2, decreases the rate of release, enabling reduced concentrations to be used while enhancing osteoinduction in both in vitro and in vivo models.

Production and Characterization of Bioactive and Antimicrobial Titanium Oxide Surfaces with Silver Nanoparticles and a Poly(lactic Acid) Microfiber Coating

Silver nanoparticles (AgNp) were deposited on highly porous TiO2 surfaces by the dripping of a colloidal AgNp solution to provide antimicrobial activity. Micro-porous TiO2 surfaces were obtained on commercially pure titanium by micro-arc oxidation in an electrolyte containing Ca and P precursors. In addition, as silver can be toxic to cells, these surfaces were uniformly covered with the biocompatible and bioresorbable poly(lactic acid) (PLA) polymer by electrospinning, aiming at promoting a controlled release of silver ions to the medium. The resulting AgNp-containing surfaces were characterized by scanning electron microscopy (SEM), energy dispersive spectrometry (EDS) and X-ray diffraction (XRD), and in vitro assays were performed to evaluate their antimicrobial activity and bioactivity. Tests revealed that the surfaces showed antimicrobial activity against Staphylococcus aureus, with better results for the surfaces without PLA. However, all the surfaces presented good biocompatibility in assays with mouse MC3T3-E1 pre-osteoblasts, and greater cell differentiation for the polymer-coated surfaces. Finally, the PLA ultrafine fibers electrospun on the TiO2/AgNp surfaces allowed a controlled release of silver ions in the phosphate-buffered saline (PBS) medium.

Solvent/non-solvent treatment as a method for surface coating of poly(ε-caprolactone) 3D-printed scaffolds with hydroxyapatite

Introduction Over the last decades numerous new materials and techniques for bone tissue engineering have been developed. The use of bioresorbable polymeric scaffolds is one of the most promising techniques for surgical management of bone defects. However, the lack of bioactive properties of biodegradable polymers restricts the area of their application for bone tissue engineering.The aim of study was to apply solvent/non-solvent treatment to coat the surface of 3D-printed bioresorbable poly(ε-caprolactone) scaffolds with bioactive hydroxyapatite particles and report on the physicochemical properties of the resulting materials.Material and Methods In the present study, biomimetic poly(ε-caprolactone) scaffolds were 3D-printed via fused deposition modeling technology and their surface was treated with the solvent/non-solvent method for coating with bioactive particles of hydroxyapatite.Results It has been found that treatment in the mixture of toluene and ethanol is suitable for the coating of poly(ε-caprolactone) scaffolds with hydroxyapatite. The scaffolds maintain porous structure after treatment while hydroxyapatite particles form homogeneous coating. The amount of hydroxyapatite on the treated scaffolds was 5.7 ± 0.8 wt. %.Discussion The proposed method ensures a homogeneous coating of outer and inner surfaces of the poly(ε-caprolactone) scaffolds with hydroxyapatite without a significant impact on the structure of a scaffold. Fourier-transform infrared spectroscopy confirmed that the solvent/non-solvent treatment has no effect on the chemical structure of PCL scaffolds.Conclusion Coating of biomimetic 3D-printed PCL scaffolds with bioactive hydroxyapatite by the solvent/non-solvent treatment has been successfully carried out. Upon coating, scaffolds retained their shape and interconnected porous structure and adsorbed hydroxyapatite particles that were uniformly distributed on the surface of the scaffold.

A Novel Achilles Tendon Repair Technique Utilizing a Bio-Composite Scaffold for a Sub-Acute Tear.

Achilles tendon ruptures are prevalent musculoskeletal injuries accounting for 20% of all large tendon ruptures with a re-rupture rate of 2.1-8.8%. Ineffectual management of these injuries can lead to a significant loss in push-off strength and overall ankle function. The field of orthopedic surgery has shown an increasing interest in biologic augmentation. Encouraged by its success in various other applications, this approach holds promise for potentially enhancing outcomes in Achilles tendon repairs, especially in poor tendon tissue. The BioBrace® (ConMed, New Haven, Connecticut) is a biocomposite scaffold made of highly porous type I collagen and bioresorbable poly (L-Lactide) (PLLA) microfilaments. It can be applied in conjunction with Achilles tendon repair or reconstruction. It provides immediate strength to the augmented repair upon implantation and simultaneously promotes new, organized tissue growth throughout its resorptive phase. Here, we outline a technique to effectively augment an acute Achilles tendon repair utilizing the BioBrace® reinforced bio-inductive implant.

A Flexible and Biodegradable Piezoelectric‐Based Wearable Sensor for Non‐Invasive Monitoring of Dynamic Human Motions and Physiological Signals

AbstractRecent progress in flexible sensors and piezoelectric materials has enabled the development of continuous monitoring systems for human physiological signals as wearable and implantable medical devices. However, their non‐degradable characteristics also lead to the generation of a significant amount of non‐decomposable electronic waste (e‐waste) and necessitate a secondary surgery for implant removal. Herein, a flexible and biodegradable piezoelectric material for wearable and implantable devices that addresses the problem of secondary surgery and e‐waste while providing a high‐performance platform for continuous and seamless monitoring of human physiological signals and tactile stimuli is provided. The novel composition of bioresorbable poly(l‐lactide) and glycine leads to flexible piezoelectric devices for non‐invasive measurement of artery pulse signals in near‐surface arteries and slight movement of the muscle, including the trachea, esophagus, and movements of joints. The complete degradability of piezoelectric film in phosphate‐buffered saline at 37 °C is also shown. The developed pressure sensor exhibits high sensitivity of 13.2 mV kPa−1 with a response time of 10 ms and shows good mechanical stability. This piezoelectric material has comparable performance to commonly used non‐degradable piezoelectric materials for measuring physiological signals. It can also be used in temporary implantable medical devices for monitoring due to its degradable nature.

Bioresorbable Poly (L-Lactic Acid) Flow Diverter Versus Cobalt-Chromium Flow Diverter: In Vitro and In Vivo Analysis.

Permanent metallic flow diverter (FD) implantation for treatment of intracranial aneurysms requires antiplatelet therapy for an unclear duration and restricts postprocedural endovascular access. Bioresorbable FDs are being developed as a solution to these issues, but the biological reactions and phenomena induced by bioresorbable FDs have not been compared with those of metallic FDs. We have developed a bioresorbable poly (L-lactic acid) FD (PLLA-FD) and compared it with an FD composed of cobalt-chromium and platinum-tungsten (CoCr-FD). FD mechanical performance and in vitro degradation of the PLLA-FD were evaluated. For in vivo testing in a rabbit aneurysm model, FDs were implanted at the aneurysm site and the abdominal aorta in the PLLA-FD group (n=21) and CoCr-FD group (n=15). Aneurysm occlusion rate, branch patency, and thrombus formation within the FD were evaluated at 3, 6, and 12 months. Local inflammation and neointima structure were also evaluated. Mean strut, porosity, and pore density for the PLLA-FD were 41.7 μm, 60%, and 20 pores per mm2, respectively. The proportion of aneurysms exhibiting a neck remnant or complete occlusion did not significantly differ between the groups; however, the complete occlusion rate was significantly higher in the PLLA-FD group (48% versus 13%; P=0.0399). Branch occlusion and thrombus formation within the FD were not observed in either group. In the PLLA-FD group, CD68 immunoreactivity was significantly higher, but neointimal thickness decreased over time and did not significantly differ from that of the CoCr-FD at 12 months. Collagen fibers significantly predominated over elastic fibers in the neointima in the PLLA-FD group. The opposite was observed in the CoCr-FD group. The PLLA-FD was as effective as the CoCr-FD in this study and is feasible for aneurysm treatment. No morphological or pathological problems were observed with PLLA-FD over a 1-year period.

Fine Tuning of the Mechanical Properties of Bio-Based PHB/Nanofibrillated Cellulose Biocomposites to Prevent Implant Failure Due to the Bone/Implant Stress Shielding Effect

A significant mechanical properties mismatch between natural bone and the material forming the orthopedic implant device can lead to its failure due to the inhomogeneous loads distribution, resulting in less dense and more fragile bone tissue (known as the stress shielding effect). The addition of nanofibrillated cellulose (NFC) to biocompatible and bioresorbable poly(3-hydroxybutyrate) (PHB) is proposed in order to tailor the PHB mechanical properties to different bone types. Specifically, the proposed approach offers an effective strategy to develop a supporting material, suitable for bone tissue regeneration, where stiffness, mechanical strength, hardness, and impact resistance can be tuned. The desired homogeneous blend formation and fine-tuning of PHB mechanical properties have been achieved thanks to the specific design and synthesis of a PHB/PEG diblock copolymer that is able to compatibilize the two compounds. Moreover, the typical high hydrophobicity of PHB is significantly reduced when NFC is added in presence of the developed diblock copolymer, thus creating a potential cue for supporting bone tissue growth. Hence, the presented outcomes contribute to the medical community development by translating the research results into clinical practice for designing bio-based materials for prosthetic devices.

A Novel Distal Biceps Rupture Repair Technique Utilizing a Biocomposite Scaffold.

Distal biceps tendon ruptures are uncommon injuries that have a re-rupture rate of 1.2% - 6%. In severe traumatic injuries or chronic injuries, a distal biceps tendon repair may require augmentation due to insufficient tissue quality. Unsuccessful treatment of these injuries can result in the loss of approximately 40% of supination strength and 30% of elbow flexion strength. There has been a growing interest in biologic augmentation in orthopedic surgery, and its incorporation into distal biceps tendon repairs has increased as well. Established bio-inductive implants and dermal allografts have been shown to be of benefit; however, these biologics have drawbacks such as failure to incorporate at time of implantation, lack of structural strength, and technical difficulty of implantation. The BioBrace® (ConMed, New Haven, CT) is a bio-inductive, biocomposite scaffold that is composed of highly porous type I collagen and bio-resorbable poly (L-Lactide) (PLLA) microfilaments. It can be used in conjunction with distal biceps tendon repair or reconstruction. It has the advantage of providing strength to the augmented repair at time zero of implantation, while also demonstrating the ability to induce new organized tissue growth throughout its resorptive phase. We describe a technique to successfully augment a distal biceps tendon repair using the BioBrace®.

A novel approach to evaluate the mechanical responses of elastin-like bioresorbable poly(glycolide-co-caprolactone) (PGCL) suture

Poly(glycolide-co-caprolactone) (PGCL) has become a novice to the bioresorbable suture owing to the synergistic properties taken from the homo-polyglycolide (PGA) and polycaprolactone (PCL) such as excellent bioresorption and flexibility. In addition to under conventional monotonic loading, the understanding of mechanical responses of PGCL copolymers under complex loading conditions such as cyclic and stress relaxation is crucial for its application as a surgical suture. Consequently, the present work focuses on evaluating the mechanical responses of PGCL sutures under monotonic, cyclic, and stress relaxation loading conditions. Under monotonic loading, the stress-strain behavior of the PGCL suture was found to be non-linear with noticeable strain-rate dependence. Under cyclic loading, inelastic responses including stress-softening, hysteresis and permanent set were observed. During cyclic loading, both stress-softening and hysteresis were found to increase with the maximum strain. In multi-step stress relaxation, the PGCL sutures were observed to exhibit a strong viscoelastic response. In an attempt to describe the relationship between the stress-relaxation and strain-induced crystallization (SIC) occurring during the loading and relaxation processes, a schematic illustration of the conformational change of polymer chains in PGCL sutures was proposed in this work. Results showed that SIC was dependent on the strain level as well as the loading and relaxation durations. The inelastic phenomena observed in PGCL sutures can be thus correlated to the combined effect of stress relaxation and SIC.

Culture of rat mesenchymal stem cells on PHBV-PCL scaffolds: analysis of conditioned culture medium by FT-Raman spectroscopy.

Mesenchymal stem cells (MSCs) have great potential for application in cell therapy and tissue engineering procedures because of their plasticity and capacity to differentiate into different cell types. Given the widespread use of MSCs, it is necessary to better understand some properties related to osteogenic differentiation, particularly those linked to biomaterials used in tissue engineering. The aim of this study was to develop an analysis method using FT-Raman spectroscopy for the identification and quantification of biochemical components present in conditioned culture media derived from MSCs with or without induction of osteogenic differentiation. All experiments were performed between passages 3 and 5. For this analysis, MSCs were cultured on scaffolds composed of bioresorbable poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) and poly(ε-caprolactone) (PCL) polymers. MSCs (GIBCO®) were inoculated onto the pure polymers and 75:25 PHBV/PCL blend (dense and porous samples). The plate itself was used as control. The cells were maintained in DMEM (with low glucose) containing GlutaMAX® and 10% FBS at 37oC with 5% CO2 for 21 days. The conditioned culture media were collected and analyzed to probe for functional groups, as well as possible molecular variations associated with cell differentiation and metabolism. The method permitted to identify functional groups of specific molecules in the conditioned medium such as cholesterol, phosphatidylinositol, triglycerides, beta-subunit polypeptides, amide regions and hydrogen bonds of proteins, in addition to DNA expression. In the present study, FT-Raman spectroscopy exhibited limited resolution since different molecules can express similar or even the same stretching vibrations, a fact that makes analysis difficult. There were no variations in the readings between the samples studied. In conclusion, FT-Raman spectroscopy did not meet expectations under the conditions studied.

The Influence of Novel, Biocompatible, and Bioresorbable Poly(3-hydroxyoctanoate) Dressings on Wound Healing in Mice.

The human body's natural protective barrier, the skin, is exposed daily to minor or major mechanical trauma, which can compromise its integrity. Therefore, the search for new dressing materials that can offer new functionalisation is fully justified. In this work, the development of two new types of dressings based on poly(3-hydroxyoctanoate) (P(3HO)) is presented. One of the groups was supplemented with conjugates of an anti-inflammatory substance (diclofenac) that was covalently linked to oligomers of hydroxycarboxylic acids (Oli-dicP(3HO)). The novel dressings were prepared using the solvent casting/particulate leaching technique. To our knowledge, this is the first paper in which P(3HO)-based dressings were used in mice wound treatment. The results of our research confirm that dressings based on P(3HO) are safe, do not induce an inflammatory response, reduce the expression of pro-inflammatory cytokines, provide adequate wound moisture, support angiogenesis, and, thanks to their hydrophobic characteristics, provide an ideal protective barrier. Newly designed dressings containing Oli-dicP(3HO) can promote tissue regeneration by partially reducing the inflammation at the injury site. To conclude, the presented materials might be potential candidates as excellent dressings for wound treatment.

Bioresorbable PPDO sliding-lock stents with optimized FDM parameters for congenital heart disease treatment

Stent implantation has been a promising therapy for congenital heart disease (CHD) due to better efficacy. Compared to permanent metal stents, bioresorbable polymer stents have shown a great advantage in accommodating the vascular growth of pediatric patients, but the application is still limited due to inferior radial strength. Here, bioresorbable poly(p-dioxanone) (PPDO) sliding-lock stents for CHD treatment were fabricated by fused deposition modeling (FDM). The effects of FDM processing parameters, including nozzle temperature, bed temperature, layer thickness, and printing speed, on the mechanical properties of PPDO parts were investigated to optimize the processing condition to enhance the radial strength of stents. Finite element analysis (FEA) was also used to evaluate the mechanical properties of stents. PPDO sliding-lock stents fabricated under optimized FDM parameters showed radial strength of 3.315 ± 0.590 N/mm, superior to benchmark commercial metal stents. Radial strength curve and compression behavior of PPDO sliding-lock stents were investigated. Results of FEA exhibited that strut width, shape of the mesh cell and surface coverage ratio had an impact on the compression force of PPDO sliding-lock stents. PPDO sliding-lock stents fabricated with optimized FDM parameters show favorable mechanical performance and meet the requirement of CHD treatment.

Development of three-dimensionally printed vascular stents of bioresorbable poly(l-lactide-co-caprolactone).

With the ripening of 3D printing technology and the discovery of a variety of printable materials, 3D-printed vascular stents provide new treatment options for patients with angiocardiopathy. Bioresorbable stent not only combines the advantages of metallic stent and drug-coated balloon, but also avoids the disadvantages of them. 3D printing is also an economical and efficient way to produce stents and makes it possible to construct complex structures. In this study, stents made from poly(l-lactic acid) (PLLA), poly(ε-caprolactone) (PCL) and poly(l-lactide-co-caprolactone) (PLCL) were manufactured by 3D printing and evaluated for radial strength, crystallinity and molecular weight. PLCL copolymerized by different proportions of lactic acid and caprolactone showed different mechanical and degradation properties. This demonstrated the potential of 3D printing as a low-cost and high throughput method for stent manufacturing. The PLLA and PLCL 95/5 stents had similar mechanical properties, whereas PLCL 85/15 and PCL stents both had relatively low radial strength. In general, PLCL 95/5 had a faster degradation rate than PLLA. These two materials were made into peripheral vascular bioresorbable scaffolds (BRS) and further studied by additional bench testing. PLCL 95/5 peripheral BRS had superior mechanical properties in terms of flexural/bending fatigue and compression resistance.

Knee Medial Collateral Ligament Augmentation With Bioinductive Scaffold: Surgical Technique and Indications

The medial collateral ligament (MCL) is the most commonly injured ligament of the knee; however, only a minority of cases require surgical intervention. Classically, isolated grade I and II MCL injuries are treated nonoperatively whereas isolated grade III injuries may be treated with surgery. High-grade MCL injuries are frequently associated with concomitant knee ligamentous injuries, particularly the anterior cruciate ligament. Nonetheless, MCL repair or reconstruction is generally reserved for patients with persistent valgus instability after failed nonoperative management. Synthetic and biological implants are increasing in popularity to augment repairs and reconstructions for biomechanical reinforcement and promotion of the native healing response to hasten rehabilitation. The BioBrace (Biorez, New Haven, CT) is a bioinductive scaffold composed of highly porous type I collagen and bioresorbable poly(L-lactide) microfilaments, providing an environment for soft-tissue regeneration and mechanical support. The purpose of this article is to describe the surgical technique and relative indications for the BioBrace in knee MCL ligament repairs and reconstructions.

Arthroscopic Rotator Cuff Repair Technique Using a Bio-Composite Scaffold for Tissue Augmentation

The use of biologics and rotator cuff augmentation have seen significant growth in interest to combat complications of rotator cuff retear after arthroscopic rotator cuff repair. Bio-inductive implants are used to induce new tissue formation; however, they lack structural strength at the time of implantation. Conversely, dermal allografts are used to provide structural strength at implantation, but they do not allow for sufficient tissue incorporation and carry inherent risks of allograft tissue. The BioBrace™ (Biorez, New Haven, CT) is a bio-inductive scaffold composed of highly porous type I collagen and bio-resorbable poly (l-lactide) microfilaments developed to combat the latter drawbacks. The unique bio-composite properties provide the ability to combine the benefits of bio-induction and strength into a single implant. We propose a successful, reproducible technique for the implantation of BioBrace for rotator cuff augmentation.

Effects of integrated bioceramic and uniaxial drawing on mechanically-enhanced fibrogenesis for bionic periosteum engineering

Periosteum is clinically required for the management of large bone defects. Attempts to exploit the periosteum’s participation in bone healing, however, have rarely featured biological and mechanical complexity for the scaffolds relevant to translational medicine. In this regard, we report engineering of bioinspired periosteum with co-delivery of ionic and geometry cues. The scaffold demonstrated microsheet-like fibre morphology and was developed based on bioresorbable poly(-caprolactone) and bioactive copper-doped tricalcium phosphate (Cu-TCP). A coordinated interaction was found between the effects of Cu-TCP addition and uniaxial drawing, leading to tunable fibrogenesis for different fibre morphologies, organisation, and surface wettability. The coordination resulted in significant enhancements in Young’s Modulus, yield stress and ultimate stress along fibrous alignment, without causing reductions across fibres. This demonstrated mechanical anisotropy of the scaffold similar to natural periosteum, and seeding with mouse calvarial preosteoblasts, the scaffold supported cell alignment with deposition of CaP-like nodules and extracellular matrix. This work provides new insights on periosteum engineering with osteo-related composite fibres. The artificial periosteum can be used in clinical settings to facilitate repair of large bone defects.

Influence of parameters on mechanical properties of poly (L-lactic acid) helical stents.

With better biocompatibility, bioresorbable poly (L-lactic acid) (PLLA) helical stents are expected to replace the commonly used metallic stents. However, due to the great difference between the material properties of PLLA and those of metals, the current research results on mechanical properties of stents will not be applicative. In this article, the effects of i on the radial compression performance and bending stiffness of PLLA helical stents were systematically studied, and the effect of temperature on the radial compression performance of the helical stent was investigated. The findings obtained indicate that the reduction of initial pitch angle and initial diameter can enhance the radial compression performance. The reduction of initial pitch angle and the increase of initial diameter can weaken the bending stiffness of the helical stent. Moreover, the increase of temperature will reduce the radial stiffness and peak compression force of the helical stent. A favorable agreement between the theoretical and experimental results of radial compression properties was found in stents with the initial pitch angle between 14° and 21° and all initial diameters. This work can provide suggestions for the use of the theoretical formula in structure design of the helical stent.

Novel Self-expanding Shape-Memory Bioresorbable Peripheral Stent Displays Efficient Delivery, Accelerated Resorption, and Low Luminal Loss in a Porcine Model

Objective and Design: The search for improved stenting technologies to treat peripheral artery disease is trending toward biodegradable self-expanding shape-memory stents that, as of now, still suffer from the acute trade-off between deliverability and luminal stability: Higher deliverability leads to lower lumen stability, vessel recoil, and stent breakage. This study was aimed at the development and testing of a self-expanding bioresorbable poly(l,l-lactide-co-ε-caprolactone) stent that was designed to produce confident self-expansion after efficient crimping, as well as quick bioresorption, and sufficient radial force. Materials and Methods: Bench tests were employed to measure shape-memory properties, radial force, and hydrolytic degradation of the stent. The porcine model was employed to study deliverability, lumen stability, biocompatibility, and stent integrity. A total of 32 stents were implanted in the iliac arteries of 16 pigs with 15 to 180 day follow-up periods. The stented vessels were studied by angiography and histological evaluation. Results: Recovery of the diameter of the stent due to shape-memory effect was equal to 90.6% after 6Fr crimping and storage in refrigeration for 1 week. Radial force measured after storage was equal to 0.7 N/mm. Technical success of implantation in pigs (after the delivery implemented by pusher) was 94%. At 180 days, no implanted stents were found to be fragmented: All of the devices remained at the site of implantation with no stent migration and all stents retained their luminal support. Only moderate inflammation and neoepithelialization were detected by histological assessment at 60, 90, 120, and 180 days. Lumen loss at 180 days was less than 25% of the vessel diameter. Conclusions: The stent with the mechanical and chemical properties described in this study may present the optimal solution of the trade-off between deliverability and luminal stability that is necessary for designing the next generation stent for endovascular therapy of peripheral arterial disease.

Thiol‐Mediated Chain Transfer as a Tool to Improve the Toughness of Acrylate Photo‐Crosslinked Poly(ε‐caprolactone)

AbstractHerein, a straightforward approach is reported to obtain photo‐crosslinked, bioresorbable poly(ε‐caprolactone) (PCL) based networks covering a range of mechanical properties (elongation at break from 203 ± 53 up to 707 ± 101% and ultimate strength from 6.8 ± 2.2 to 13.9 ± 1.5 MPa) via alteration of the network topology. Exploiting multifunctional thiols for crosslinking of acrylate‐terminated PCL is an effective method to alter the mechanical properties of photo‐crosslinked networks due to the chain transferring ability of the thiols. By controlling the thiol to acrylate ratio, the Young's modulus, elongation at break and ultimate strength can be significantly altered. The materials described in this work can be considered potential candidates for light‐based 3D‐printing and to serve tissue engineering applications.