Advanced tissue engineering scaffolds for postoperative cancer patients

Abstract

Event Abstract Back to Event Advanced tissue engineering scaffolds for postoperative cancer patients Lin Guo1*, Qilong Zhao1 and Min Wang1* 1 The University of Hong Kong, Department of Mechanical Engineering, Hong Kong, SAR China Introduction: Cancers are major threats to human lives. Surgical removal of tumors is currently the main cancer treatment. But the surgery may result in post-operation tissue dysfunction. The risk of cancer recurrence in patients is also a major problem. It is important to develop new approaches for regenerating tissues at surgical site and at the same time preventing cancer recurrence. In scaffold-based tissue engineering, electrospun scaffolds possess desirable properties for promoting the regeneration of human tissues [1]. And Au nanoparticle (AuNP)-based theranostics are investigated as novel tools for early cancer detection and cancer treatment [2]. This study investigated the fabrication and properties of novel nanofibrous scaffolds incorporated with theranostics for cancer patients. Materials and Methods: Folic acid-chitosan-capped gold (Au@CS-FA) NPs with highly branched AuNP core were made via one-pot synthesis [3]. CS-FA conjugate was the shell on NPs and FA would provide high tumor targeting ability. For cancer detection, R6G was embedded in theranostics for generating SERS signals. Coaxial electrospray [4] was used to encapsulate theranostics in core-shell structured PLGA microspheres. Multifunctional scaffolds were fabricated using the novel dual-source dual-power electrospinning and coaxial electrospray technique, with electrospinning producing nanofibrous PLGA (LA:GA=75:25) scaffolds and coaxial electrospray forming theranostic-containing PLGA (LA:GA=50:50) microspheres. The structure and properties of theranostics, theranostic-containing microspheres, and complex scaffolds were then studied. Results and Discussion: Microspheres containing Au@CS-FA theranostics in the aqueous core could be made via coaxial electrospray (Fig.1a) and nanofibrous PLGA scaffolds could be produced via electrospinning (Fig.1c). Using dual-source dual-power electrospinning and coaxial electrospray and adjusting process parameters, multifunctional scaffolds containing theranostic-encapsulated polymer microspheres were fabricated (Fig.1b). Microspheres were randomly distributed in nanofibrous scaffolds, and the core-shell structure of microspheres embedded in scaffolds was clearly seen under TEM. Immersion tests in PBS were conducted and after 21-day degradation in PBS, PLGA shell of microspheres was broken down (Fig.2a) and theranostics were released (Fig.2b). As nanofibers in scaffolds were made of PLGA 75/25, they degraded faster than PLGA 50/50 microspheres and hence tissue regeneration would occur first in the surgical site of patients. Theranostics were studied before encapsulation in microspheres and after release in scaffolds. The released Au@CS-FA theranostics were found to retain the structure and morphology of original theranostics, still exhibiting highly branched AuNP core with many irregular tips. Strong SERS signals were seen from Au@CS-FA theranostics after their release in scaffolds (Fig.2c), indicating their ability for cancer detection. Conclusion: Using the novel fabrication technique, multifunctional scaffolds could be made for cancer patients for tissue regeneration at the surgical site and for detecting and treating cancer recurrence. The Au@CS-FA theranostics could be released in nanofibrous scaffolds after the shell of polymer microspheres had degraded. The released theranostics gave strong SERS signals, indicating their potential for cancer cell detection. This work was supported by Hong Kong Research Grants Council through a GRF Grant (HKU717713E).