Engineering considerations of iPSC-based personalized medicine

Abstract

Personalized medicine aims to provide tailored medical treatment that considers the clinical, genetic, and environmental characteristics of patients. iPSCs have attracted considerable attention in the field of personalized medicine; however, the inherent limitations of iPSCs prevent their widespread use in clinical applications. That is, it would be important to develop notable engineering strategies to overcome the current limitations of iPSCs. Such engineering approaches could lead to significant advances in iPSC-based personalized therapy by offering innovative solutions to existing challenges, from iPSC preparation to clinical applications. In this review, we summarize how engineering strategies have been used to advance iPSC-based personalized medicine by categorizing the development process into three distinctive steps: 1) the production of therapeutic iPSCs; 2) engineering of therapeutic iPSCs; and 3) clinical applications of engineered iPSCs. Specifically, we focus on engineering strategies and their implications for each step in the development of iPSC-based personalized medicine.

Keywords: Engineering strategies; Induced pluripotent stem cells; Next-generation therapeutics; Personalized medicine.

Fig. 1

Overview of iPSC engineering steps for personalized medicine. Step 1: Production of therapeutic iPSCs (three approaches). Approach 1. Production of in-hospital iPSCs. Patient biopsy collected from skin, blood, liver, hair follicles, or urine is reprogrammed by reprogramming factors integrated with viral and non-viral vectors for the production of iPSCs. In-hospital iPSCs are then expanded for further use. Approach 2. Production of commercialized iPSCs. Patient biopsy is collected from the hospital and sent to a company for commercialization. Fully automated processes are used for commercialized iPSC production, followed by a quality assessment. Approach 3. Production of personalized iPSC lines. Patient biopsy is collected from the hospital and sent to a company. Samples are reprogrammed to produce commercialized iPSCs. The commercialized iPSCs are further expanded using bioreactor systems. Purification stages should be performed before the establishment of personalized iPSC lines. Step 2. Engineering of therapeutic iPSCs (four approaches). Approach 1. Engineering iPSCs for paracrine effects. iPSCs release different types of secretomes and regulate cell fate, such as proliferation, angiogenesis, and cell migration. Approach 2. Engineering iPSCs for differentiation. iPSCs are differentiated by electromagnetic factors, mechanical factors, and biomaterial factors. Approach 3. Engineering iPSCs for biomodulation. Different types of engineering techniques are used for biomodulation. iPSC-derived immune cells (T-cells, NK cells) are used for immunomodulation, whereas CRISPR, TALEN, and ZINC fingers are used for genetic modification, which includes disruption, transgene insertion, and gene correction. Approach 4. Engineering iPSCs for pharmaceuticals. Engineering strategies such as organoids, in vitro models, and extracellular vesicles are used for pharmaceuticals. Step 3. Application of engineered iPSCs (three approaches used in various combinations). Approach 1. Tissue regeneration. Engineered iPSCs can either be directly injected or transplanted with scaffolds. Approach 2. Cancer therapy. iPSCs are used for tumor regression through various combinations of engineering strategies. Approach 3. Drug development. Engineered iPSCs are used for drug development and drug screening

Fig. 2

Preparation and automation of iPSCs for personalized medicine. a Mass production of human iPSCs in stirred-tank bioreactors. Hematopoietic differentiation of human iPSCs in stirred-tank bioreactors. Reproduced with permission from Ref. [41]. b Scalable system for iPSC generation, where uniform gelatin methacryloyl microcarriers are fabricated via the microfluidic-based emulsification process. Reproduced with permission from Ref. [45]. c Nanopuncture-assisted iPSC reprogramming via the intracellular delivery of mini-intronic plasmids (MIP) and human neonatal dermal fibroblast (HDF) cells. Reproduced with permission from Ref. [79]. d A microfluidic device is designed to create a transient membrane hole in the cell surface when they are passed through the device because of the rapid deformation of cells. Reproduced with permission from Ref. [80]. e Long-term maintenance of human iPSCs by an automated cell culture system, which helps human iPSCs maintain their undifferentiated state for 60 days. Human iPSCs generated by this system can differentiate into three germ layer cells as well as dopaminergic neurons and pancreatic cells. Reproduced with permission from Ref. [15]. f An automated procedure for the iPSC line expansion through culturing and reprograming from human fibroblast in a controlled clean room environment. This platform is designed with a liquid handling unit, incubator, robotic arm, microscope, picker, plate reader, centrifuge, and microtiter plate. Reproduced with permission from Ref. [65]

Fig. 3

Engineering strategies and applications of iPSCs for personalized medicine. a Conditioned medium generated from umbilical cord-derived mesenchymal stem cells (uMSC-CdM) and iPSC-derived mesenchymal stem cells (iMSC-CdM) effectively promoted cutaneous wound healing. Reproduced with permission from Ref. [16]. b 3D bioprinting of a human iPSC-derived MSC-loaded scaffold for regeneration of the uterine endometrium. The preparation of human iMSC-loaded hydrogels was followed by the construction of the engineered scaffold through the 3D printing process. The engineered scaffolds were cultured in vitro for three days and then transplanted, and the structure and function of the endometrium were assessed after the repair of the uterine horn. Reproduced with permission from Ref. [94]. c A microdevice platform for characterizing the effect of mechanical strain magnitudes on the maturation of iPSC-cardiomyocytes. Reproduced with permission from Ref. [95]. d Human iPSC-derived NK (hnCD16iNK) cells produced from donor iPSC line with genetic engineering. The hnCD16iNK cells showed better antitumor activity on in vivo ovarian cancer model. Reproduced with permission from Ref. [96]. e Exosomes derived from iPSCs mitigate pulmonary fibrosis induced by bleomycin, with less collagen deposition. Reproduced with permission from Ref. [97]. f Gene correction, transcript analysis, and differentiation to kidney organoids. Patient-iPSC-derived kidney organoids show functional validation of a ciliopathic renal phenotype and reveal underlying pathogenetic mechanisms. Reproduced with permission from Ref. [98]

Fig. 4

Specialized applications of iPSCs for personalized medicine. a Personalized hydrogels for engineering diverse fully autologous tissue implants, which were efficiently generated by combining autologous iPSCs and extracellular matrix. As both the cells and the hydrogels are derived from the patient, they do not induce an immune response. Reproduced with permission from Ref. [175]. b The first-in-human clinical trial of iPSC-derived platelets (iPLAT1). The iPLAT1 study completed the administration of iPSC-platelets for the first time and confirmed the safety in an allo-PTR patient who would otherwise have no HPA-compatible donor. No adverse events were observed during the administration of autologous iPLAT1. Reproduced with permission from Ref. [177]. c Development of an engineered exosome delivery system. The engineered exosomes, BT-Exo-siShn3, targeted osteoblasts specifically and contained siRNA to silence the Shn3 gene, which enhanced osteogenic differentiation and decreased autologous RANKL expression. Reproduced with permission from Ref. [178]. d Drug screening platform using iPSCs derived from a patient with ultrarare diseases. The iPSC platform validated the safety and efficacy of the screened drugs. The efficacy of the screened drugs was also investigated in a patient with Leigh-like syndrome, who showed an enhanced physical state after three years of clinical trials. Reproduced with permission from Ref. [179]