Rationale:: More than 25 million individuals have heart failure worldwide, with ≈4000 patients currently awaiting heart transplantation in the United States. Donor organ shortage and allograft rejection remain major limitations with only ≈2500 hearts transplanted each year. As a theoretical alternative to allotransplantation, patient-derived bioartificial myocardium could provide functional support and ultimately impact the treatment of heart failure. Objective:: The objective of this study is to translate previous work to human scale and clinically relevant cells for the bioengineering of functional myocardial tissue based on the combination of human cardiac matrix and human induced pluripotent stem cell–derived cardiomyocytes. Methods and Results:: To provide a clinically relevant tissue scaffold, we translated perfusion-decellularization to human scale and obtained biocompatible human acellular cardiac scaffolds with preserved extracellular matrix composition, architecture, and perfusable coronary vasculature. We then repopulated this native human cardiac matrix with cardiomyocytes derived from nontransgenic human induced pluripotent stem cells and generated tissues of increasing 3-dimensional complexity. We maintained such cardiac tissue constructs in culture for 120 days to demonstrate definitive sarcomeric structure, cell and matrix deformation, contractile force, and electrical conduction. To show that functional myocardial tissue of human scale can be built on this platform, we then partially recellularized human whole-heart scaffolds with human induced pluripotent stem cell–derived cardiomyocytes. Under biomimetic culture, the seeded constructs developed force-generating human myocardial tissue and showed electrical conductivity, left ventricular pressure development, and metabolic function. Conclusions:: Native cardiac extracellular matrix scaffolds maintain matrix components and structure to support the seeding and engraftment of human induced pluripotent stem cell–derived cardiomyocytes and enable the bioengineering of functional human myocardial-like tissue of multiple complexities.

Malnutrition is a frequent comorbidity in head and neck cancer patients and has been shown to impair immunotherapy response in other cancer types. The geriatric nutritional risk index (GNRI) assesses malnutrition using the patient’s ideal weight, actual weight, and serum albumin. The aim of this study was to evaluate the prognostic relevance of malnutrition as determined by the GNRI for the response to immunotherapy in recurrent and/or metastatic head and neck squamous cell carcinoma (R/M HNSCC). A total of 162 patients with R/M HNSCC who received immune checkpoint inhibitors were included. The associations between the GNRI and progression-free survival (PFS), overall survival (OS), and the disease control rate (DCR) were computed. Univariable analysis showed worse PFS for GNRI ≤ 98 (p < 0.001), ECOG performance status (PS) ≥ 2 (p = 0.012), and enteral (p = 0.009) and parenteral (p = 0.015) nutritional supplementation, and worse OS for GNRI < 92 (p < 0.001), ECOG PS ≥ 2 (p < 0.001), and enteral (p = 0.008) and parenteral (p = 0.023) nutritional supplementation. In our multivariable model, GNRI ≤ 98 (p = 0.012) and ECOG PS ≥ 2 (p = 0.025) were independent prognostic factors for PFS. For OS, GNRI < 92 (p < 0.001) and ECOG PS ≥ 2 (p < 0.001) were independent prognostic factors. A GNRI ≤ 98 was significantly associated with a lower DCR compared to a GNRI > 98 (p = 0.001). In conclusion, our findings suggest that the GNRI may be an effective predictor for response to immunotherapy in R/M HNSCC.

Full-thickness skin loss is a challenging problem due to limited reconstructive options, demanding 75 million surgical procedures annually in the United States. Autologous skin grafting is the gold standard treatment, but results in donor-site morbidity and poor aesthetics. Numerous skin substitutes are available on the market to date, however, none truly functions as full-thickness skin due to lack of a vascular network. The creation of an autologous full-thickness skin analogue with a vascular pedicle would result in a paradigm shift in the management of wounds and in reconstruction of full-thickness skin defects. To create a clinically relevant foundation, we generated an acellular skin flap scaffold (SFS) with a perfusable vascular pedicle of clinically relevant size by perfusion decellularization of porcine fasciocutaneous flaps. We then analyzed the yielded SFS for mechanical properties, biocompatibility, and regenerative potential in vitro and in vivo. Furthermore, we assessed the immunological response using an in vivo model. Finally, we recellularized the vascular compartment of an SFS and reconnected it to a recipient's blood supply to test for perfusability. Perfusion decellularization removed all cellular components with preservation of native extracellular matrix composition and architecture. Biaxial testing revealed preserved mechanical properties. Immunologic response and biocompatibility assessed via implantation and compared with native xenogenic skin and commercially available dermal substitutes revealed rapid neovascularization and complete tissue integration. Composition of infiltrating immune cells showed no evidence of allorejection and resembled the inflammatory phase of wound healing. Implantation into full-thickness skin defects demonstrated good tissue integration and skin regeneration without cicatrization. We have developed a protocol for the generation of an SFS of clinically relevant size, containing a vascular pedicle, which can be utilized for perfusion decellularization and, ultimately, anastomosis to the recipient vascular system after precellularization. The observed favorable immunological response and good tissue integration indicate the substantial regenerative potential of this platform.