Rapid and durable photochemical bonding of cartilage using the porphyrin photosensitizer verteporfin

Abstract

Objective: To evaluate the effectiveness of verteporfin as a photosensitizer to photochemically bond articular cartilage tissues and determine bond durability in vitro. Design: Bond strength induced by verteporfin over a range of concentrations and light exposure conditions was investigated using a disk-annulus model and a pushout test. Exposure was parameterized by varying either irradiance or irradiation time. Bond robustness in a cell-mediated degeneration environment was examined by exposing newly bonded samples to interleukin-1 alpha for the first 4 days of a 7-day culture period, followed by mechanical testing and biochemical and cellular viability assays. Results: Photochemical bonding using verteporfin produced high bonding shear strengths at relatively low photosensitizer concentrations. Low exposures produced by either low irradiance or short irradiation time were sufficient to produce shear strengths comparable to those previously produced with phthalocyanine photosensitizers with substantially higher light exposure. Photochemically produced bonds were resistant to cell-mediated degeneration in vitro with no evident differences in cell viability among treatments. Conclusions: Verteporfin offers distinct advantages as a photosensitizer for photochemical bonding of articular cartilage due to the production of strong, durable bonds at relatively low light exposures. Further exploration may lead to clinically feasible strategies to augment cartilage repair techniques.

Self-Organization Dynamics of Collagen-like Peptides Crosslinking Is Driven by Rose-Bengal-Mediated Electrostatic Bridges

“…Compared to suturing method, the use of PTB generates minimal scarring and fibrosis, and produces less inflammatory effects [10][11][12]. Porphyrins, phthalocyanines, phenothiazines, and xanthenes have been widely used to generate collagen crosslinking in tissues, such as articular cartilage, skin, and cornea [13,14]. In this sense, Rose Bengal (RB), belonging to the Xanthene family, is a noteworthy PS dye used as a light-activated tissue-bonding molecule due to its recent use in cornea repair therapy for human patients [15].…”

A Photochemical Crosslinking Approach to Enhance Resistance to Mechanical Wear and Biochemical Degradation of Articular Cartilage

“…Photochemical crosslinking has been demonstrated to crosslink the interface between 2 cartilage surfaces, and may enhance the integration of osteochondral grafts to native cartilage. 17 - 19 In particular, Al(III) phthalocyanine chloride tetrasulfonic acid (CASPc), a photosensitizer from the phthalocyanine group that is activated by 670 nm light, was reported to produce functional bonds between 2 cartilage surfaces without significant loss of cell viability. 17 , 19 However, whether photochemical crosslinking with CASPc enhances the mechanical properties and resistance to collagenase degradation of cartilage tissue has not been previously investigated.…”