Microparticles in Contact with Cells: From Carriers to Multifunctional Tissue Modulators

• Published in: Trends in biotechnology (Regular ed.) 2019-09, Vol.37 (9), p.1011-1028
• Main Authors: Neto, Mafalda D., Oliveira, Mariana B., Mano, João F.
• Format: Article
• Language: English
• Subjects: advanced microcarriers; Anisotropy; Bioengineering; bioinks; Biomaterials; Biomedical materials; bottom-up tissue engineering; building blocks; Cellulose; Collagen; Cultivation; Drug delivery; Drug delivery systems; Emulsion polymerization; Expansion; Geometry; in vitro 3D models; Internalization; microparticle design; Microparticles; Modulators; Organic chemistry; Polymers; State-of-the-art reviews; Three dimensional printing; Tissue engineering; Trends
• ISSN: 0167-7799; 1879-3096
• DOI: 10.1016/j.tibtech.2019.02.008

For several decades microparticles have been exclusively and extensively explored as spherical drug delivery vehicles and large-scale cell expansion carriers. More recently, microparticulate structures gained interest in broader bioengineering fields, integrating myriad strategies that include bottom-up tissue engineering, 3D bioprinting, and the development of tissue/disease models. The concept of bulk spherical micrometric particles as adequate supports for cell cultivation has been challenged, and systems with finely tuned geometric designs and (bio)chemical/physical features are current key players in impacting technologies. Herein, we critically review the state of the art and future trends of biomaterial microparticles in contact with cells and tissues, excluding internalization studies, and with emphasis on innovative particle design and applications. Promising outputs have been delivered by microparticles as microcarriers with enhanced surface area in response to high cellular demands. However, their ability to adapt to clinically translatable setups, including xeno-free conditions and the use of biodegradable materials, is still a leading-edge trend. Advances in particle design and control over their architecture and morphology, along with understanding of the role of tailorable (bio)chemical/physical aspects, enable the modulation of cellular response. Finely tailored systems may be attained through several enabling technologies and fabrication methods. Recent applications of microparticles include their exploitation as building blocks for bottom-up tissue engineering strategies, have integrated in vitro 3D cellular tissue/disease models as cue providers, and have been used as reinforcement units in bioinks for 3D bioprinting.