en نانوتکنولوژی Nanotechnology review review <div style="text-align: justify;">Hydrogels have been used for biomedical applications in recent decades. They are a perfect candidate for regenerative medicine as they resemble the extracellular matrix of native tissues. In addition, their highly hydrated structure makes them a suitable choice for drug and other therapeutics delivery. Injectable hydrogels have increasingly gained attention due to their capability for homogeneous mixing with cells and therapeutic agents, minimally invasive administration, and perfect defect filling. In this review, we discuss various mechanisms which facilitate injectability of hydrogels, including <em>in situ</em> gelling liquids, injectable gels, and injectable particles. Then, we explore the biomedical applications of injectable hydrogels, including tissue engineering, therapeutic agent delivery, and medical devices.</div> Injectable, Hydrogel, In Situ Gelling, Tissue Engineering, Drug Delivery, Nanoparticle 1 19 http://rmm.mazums.ac.ir/browse.php?a_code=A-10-733-3&slc_lang=en&sid=1 Amir Mellati amirmellati@gmail.com 10031947532846007707 10031947532846007707 No School of Advanced Technologies in Medicine, Mazandaran University of Medical Sciences, Sari, Mazandaran, Iran. Molecular and Cell Biology Research Center, Faculty of Medicine, Mazandaran University of Medical Sciences, Sari, Iran. Immunogenetics Research Center, Mazandaran University of Medical Sciences, Sari, Iran Javad Akhtari javad.akhtari@gmail.com 10031947532846007708 10031947532846007708 Yes Department of Medical Nanotechnology, School of Advanced Technologies in Medicine, Mazandaran University of Medical Sciences, Sari, Iran. Immunogenetics Research Center, Mazandaran University of Medical Sciences, Sari, Iran,