Polypropylene mesh materials have been utilized in hernia surgery for over 40 years. However, they are prone to degradation due to the body's aggressive foreign body reaction, which may cause pain or complications, forcing mesh removal from the patient. To mitigate these complications, gold nanomaterials were attached to polypropylene mesh in order to improve cellular response. Pristine samples of polypropylene mesh were exposed to hydrogen peroxide/cobalt chloride solutions to induce formation of surface carboxyl functional groups. Gold nanoparticles were covalently linked to the mesh. Scanning electron microscopy confirmed the presence of gold nanoparticles. Differential scanning calorimetry and mechanical testing confirmed that the polypropylene did not undergo any significantly detrimental changes in physicochemical properties. A WST-1 cell culture study showed an increase in cellularity on the gold nanoparticle-polypropylene mesh as compared to pristine mesh. This study showed that biocompatibility of polypropylene mesh may be improved via the conjugation of gold nanoparticles.

Decellularized allograft tissue is used for a wide array of tissue injuries and repair with tenons and ligament repair being among the most common. However, despite their frequent use there is concern over the lengthy inflammatory period and slow healing associated with allografts. One promising solution has been the use of nanoparticles. There is currently no easy, fast method to achieve consistent conjugation of nanoparticles to tissue. The available conjugation methods can be time-consuming and/or may create numerous cytotoxic byproducts. Genipin, a naturally derived crosslinking agent isolated from the fruits of Gardenia jasminoides was investigated as a conjugation agent to achieve fast, consistent crosslinking without cytotoxic byproducts. The rational of utilizing genipin is that is reacts spontaneously with amino-group-containing compounds such as proteins, collagens, and gelatins, and does not require extensive washing after conjugation. Porcine diaphragm tendons were decellularized and then immersed in cysteamine functionalized gold nanoparticles and genipin for various time points. Tissue scaffolds were tested for the degree of crosslinking, gold nanoparticle concentrations, and fibroblast attachment and biocompatibility. Results demonstrated that genipin can successfully and reproducibly attach gold nanoparticles to tissue in as little as 15 min. The genipin had no cytotoxic effects and improved fibroblast attachment and proliferation. Genipin can be used to attach gold nanoparticles to tissue in a fast, cell safe manner.

Injectable collagen microspheres (CMs) have the potential to be an excellent tool to deliver various modulatory agents or to be used as a cellular transporter. A drawback has been the difficulty in producing reliable and spherical CMs. A crosslinker‐free method to fabricate CMs was developed using liquid collagen (LC) in a water‐in‐oil emulsion process with varying concentrations of surfactant span‐80. Different emulsion times of up to 16‐hr were utilized to produce the CMs. Visual microscopy and scanning electron microscopy were utilized to determine the morphology of the CMs. To determine the fibril nature of the CMs, focus ion beam milling, energy dispersive spectroscopy, and Fourier Transformation‐Infrared spectroscopy were performed. A cell biocompatibility study was performed to assess the biocompatibility of the CMs. The results demonstrated that consistent spherical CMs were achievable by changing the span‐80 concentration. The CMs were fibrilized not only at the surface, but also at the core. Both the 1‐ and 16‐hr emulsion time demonstrated biocompatibility and it appeared that the cells preferentially adhered to the CMs. This crosslinker‐free method to fabricate CMs resulted in spherical, stable, biocompatible CMs, and could be an excellent technique for multiple tissue engineering applications.

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Introduction: Prior publications have demonstrated chemical and physical alteration of hernia mesh analyzed after explantation from the body. The specific alteration documented is oxidative degradation of polypropylene mesh fibers. An animal study recently published has demonstrated that adipose tissue attachment is present instead of reparative fibrous tissue infiltration in an average of 10.9–18.9% of the intramesh healing for a variety of clinically used knitted polypropylene mesh products; 8.0% for knitted polyester meshes. This study also found that in comparison to the knitted mesh products, non-woven polypropylene mesh reduced adipose tissue attachment to 1% or less, which was a statistically significant difference. Materials and Methods: Samples of explanted polypropylene mesh from eight patients were analyzed for the presence of adipose tissue attachment, reparative fibrous tissue infiltration, and oxidative changes. Greater adipose tissue attachment areas were compared with areas of greater reparative fibrous tissue infiltration for evidence of oxidative changes in the mesh to determine if the areas of higher adipose tissue attachment correlated with an increase in oxidative changes. Results: Intra mesh healing of clinically explanted knitted meshes demonstrated adipose tissue content from 0.0% to 49.1% per analyzed segment. The oxidation index, a measure of the degree of oxidative degradation in that portion of the mesh, was higher in seven of the eight areas of greater adipose tissue attachment than areas of greater reparative fibrous tissue infiltration. Conclusion: Adipose tissue attachment does occur in knitted and woven polypropylene hernia meshes. The presence of adipose tissue may contribute to an increase in oxidative changes in knitted polypropylene hernia mesh fibers.