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Stent insertion can serve as an effective therapy method for patients with esophageal stricture but stents with inappropriate mechanical properties lead to restenosis. To prepare a stent matching the esophageal environmental mechanics, both the NiTi spring yarn and polyester multifilament were used to produce seven kinds of stents by braiding technology. The mechanical properties of the stents were tested including compression, flexibility, and antimigration behavior. Results showed that three different parameters including spring consistency with tracks, spring content, and spring pitch altered the effective number of coils and elastic modulus, and affected the compression strength, flexibility and migration resistance of the stent. In particular, the integrated braided stent with full consistency, 12 NiTi spiral yarns, and spring pitch of 1.00 mm had the best mechanical properties among all the prototypes in this research. The compression strength, bending strength, and migration resistance were 1048.75 cN, 46.35 cN, and 3.74 N, respectively. In summary, this research presents a new preparation method for esophageal stent manufacture in the treatment of inoperable esophageal malignancies.

Orthopedic suture, as an implantable surgical device for skeletal and soft tissue connection, is vital in tendon or ligament injury repair. Resorbable therapy approaches exhibit excellent biocompatibility in the field of suture materials but lack a long-term fixation effect in orthopedic treatment. Herein, this study focused on a series of partially absorbable orthopedic sutures, which were composed of absorbable polycaprolactone (PCL) multifilament and non-absorbable ultra-high molecular weight polyethylene (UHMWPE) multifilament. Comprehensive in vitro mechanical evaluations were conducted to probe the relationship between material composition and mechanical properties of the sutures. The results showed that the partially absorbable sutures, especially P/U = 50/50 and P/U = 25/75, exhibited significant improvements in mechanical properties compared to single-material sutures. The tensile strength of P/U = 50/50 and P/U = 25/75 was 180.99 and 210.91 N, respectively, which was about two times higher than that of absorbable PCL suture P/U = 100/0 (62.42 N). Furthermore, their suture-to-suture friction force was 1.89 times and 2.51 times that of non-absorbable UHMWPE suture P/U = 0/100, respectively, which guaranteed good knot security. Compared with the clinically used orthopedic suture Ethibond (110 N), P/U = 50/50 and P/U = 25/75 also presented superior tensile properties. Notably, P/U = 50/50 and P/U = 25/75 had similar tensile curves to that of the native tendon/ligament, which might be beneficial to tissue healing. Moreover, the R2 of Eyring's model to simulate the creep curves of each suture was higher than 0.99, which indicated that Eyring's model could be used in predicting the long-term creep behavior of the sutures.

A PVA/PAAm (polyvinyl alcohol/polyacrylamide) hydrogel vascular graft reinforced by a braided fiber stent was prepared in the present work, and a series of characterizations were carried out for evaluating the comprehensive performance of the reinforced hydrogel vascular graft (RHVG), including the morphology, the mechanical properties and the biocompatibility. The results show that hydrogel with a mass ratio of 5:8 (PVA:PAAm) is the best candidate for developing an implantation-oriented vascular graft, whose overall performance is the closest to the requirements of clinical applications. The surface of the PVA/PAAm hydrogel is smooth, and the porous structure is uniform and stable. When the longitudinal strain of the RHVG was 50%, the tensile strength reached 905.6 ± 63.1 kPa, much higher than that of a swine common carotid artery (185 kPa). Moreover, the circumferential tensile strength was significantly enhanced by the integration of the stent, and the circumferential compression recovery reached 93.4 ± 6.7%, showing satisfactory structural stability. Furthermore, the suture retention force approached (9.89 ± 0.64 N), higher than that of a canine femoral artery (7.90 ± 0.36 N). More importantly, the radial dynamic compliance reached 3.11 ± 0.09% under testing pressure of 80–120 mmHg, which is 6.9 times that of a commercial expanded polytetrafluoroethylene vascular graft. Lastly, the RHVG has satisfying cytocompatibility and a low hemolysis rate. In summary, the present work may pave the way for developing a novel small-diameter vascular graft for clinical implantation.

The development of a small diameter (≤5 mm) arterial prosthesis requires the appropriate selection of materials, structure and fabrication method so as to provide adequate mechanical properties, superior biocompatibility and precise control over the diameter. In this study, 100% polyester, 100% silk fibroin and a combination of both yarns were woven into seamless tubular prototype prostheses with different basic weaves. After degumming/scouring they met a target inner diameter of 3.9±0.3 mm which demonstrates that weaving is a precise way to manufacture small caliber arterial prostheses. In conclusion, the bicomponent polyester/silk woven samples had superior mechanical properties and improved cytocompatibility compared to commercial ePTFE devices.