Hydrogels: Biomaterials for Sustained
and Localized Drug Delivery
Ganesan Keerthiga, Pallavi Gupta, and Tuhin Subhra Santra
Abstract Hydrogels are three dimensional (3D) cross-linked polymer networks
capable of holding a large volume of water. The hydrophilic polymeric system sometimes exists as a colloidal gel inside water, i.e., dispersion medium. Hydrogels aim
to mimic the 3D microenvironment of cells with the advantage of surpassing adverse
gastrointestinal effects on the drug, therefore increasing patient compliance. This
polymer-based hydrogel formulation has tunable properties such as porosity, tensile
strength, drug loading capacity, and release kinetics that contribute towards better
biocompatible hydrogel design. The monomeric units in hydrogels bind through
physical and chemical forces such as hydrophobic interaction, hydrogen bonding, UV
crosslinking, and many others. Albeit hydrogel is known for its water holding capacity
and high biocompatibility, the cytotoxicity of hydrogel depends on the polymer selection. Deformable and injectable hydrogels that can alter its physical state in room
and body temperature are in the research pipeline to avoid surgery for implantation.
Further, environmental stimuli-responsive hydrogels like pH, temperature-sensitive
hydrogels are evolving as ‘Smart drug delivery’ systems. This distinctive property
of tunable hydrogel design and formulation finds its application in sustained and
localized drug delivery. This chapter discusses the different classifications of the
hydrogel, along with its crosslinking chemistry involved. We also have summarised
various forms of hydrogel from lab scale to industrial level. Finally, this chapter also
covers the synthesis, functionalization, tailoring mechanism of the hydrogel matrix,
followed by in vitro, ex vivo, and in vivo characterization and drug loading/delivery
efficiency.
Keywords Hydrogel · 3D polymer · Nanocomposites · Stimuli-responsive
hydrogel · Controlled drug delivery
G. Keerthiga
Centre for Biotechnology, Anna University, Chennai 600032, Tamil Nadu, India
P. Gupta · T. S. Santra (B)
Department of Engineering Design, Indian Institute of Technology Madras, Chennai 600032,
Tamil Nadu, India
e-mail: tuhin@iitm.ac.in
© The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2021
T. S. Santra and L. Mohan (eds.), Nanomaterials and Their Biomedical Applications,
Springer Series in Biomaterials Science and Engineering 16,
https://doi.org/10.1007/978-981-33-6252-9_9
211
and Localized Drug Delivery
Ganesan Keerthiga, Pallavi Gupta, and Tuhin Subhra Santra
Abstract Hydrogels are three dimensional (3D) cross-linked polymer networks
capable of holding a large volume of water. The hydrophilic polymeric system sometimes exists as a colloidal gel inside water, i.e., dispersion medium. Hydrogels aim
to mimic the 3D microenvironment of cells with the advantage of surpassing adverse
gastrointestinal effects on the drug, therefore increasing patient compliance. This
polymer-based hydrogel formulation has tunable properties such as porosity, tensile
strength, drug loading capacity, and release kinetics that contribute towards better
biocompatible hydrogel design. The monomeric units in hydrogels bind through
physical and chemical forces such as hydrophobic interaction, hydrogen bonding, UV
crosslinking, and many others. Albeit hydrogel is known for its water holding capacity
and high biocompatibility, the cytotoxicity of hydrogel depends on the polymer selection. Deformable and injectable hydrogels that can alter its physical state in room
and body temperature are in the research pipeline to avoid surgery for implantation.
Further, environmental stimuli-responsive hydrogels like pH, temperature-sensitive
hydrogels are evolving as ‘Smart drug delivery’ systems. This distinctive property
of tunable hydrogel design and formulation finds its application in sustained and
localized drug delivery. This chapter discusses the different classifications of the
hydrogel, along with its crosslinking chemistry involved. We also have summarised
various forms of hydrogel from lab scale to industrial level. Finally, this chapter also
covers the synthesis, functionalization, tailoring mechanism of the hydrogel matrix,
followed by in vitro, ex vivo, and in vivo characterization and drug loading/delivery
efficiency.
Keywords Hydrogel · 3D polymer · Nanocomposites · Stimuli-responsive
hydrogel · Controlled drug delivery
G. Keerthiga
Centre for Biotechnology, Anna University, Chennai 600032, Tamil Nadu, India
P. Gupta · T. S. Santra (B)
Department of Engineering Design, Indian Institute of Technology Madras, Chennai 600032,
Tamil Nadu, India
e-mail: tuhin@iitm.ac.in
© The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2021
T. S. Santra and L. Mohan (eds.), Nanomaterials and Their Biomedical Applications,
Springer Series in Biomaterials Science and Engineering 16,
https://doi.org/10.1007/978-981-33-6252-9_9
211