Page 35 - IJB-10-3

International Journal of Bioprinting Supramolecular hydrogels as bioinks

make them suitable for complex wounds. Furthermore, (PNIPAM) (thermosensitive) block and the middle PEG
the regulated release of specific molecules, such as basic (hydrophilic) block. These polymers were able to adapt
fibroblast growth factor (bFGF) and epidermal growth to the acidic environment, attributed to the hydrophobic
factor (EGF), was reported to promote angiogenesis and hydrogen bonding synergetic interactions in the
in vitro. 154,155 gel. As evident from various reports, supramolecular
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Hybrid supramolecular hydrogels, composed of PEG hydrogels have displayed significant promise for wound
methacrylate (PEGMA) and PEGylated silver NPs (AgNPs), healing due to their exceptional properties, positioning
possess superior antibacterial properties. By utilizing host– them as effective agents for promoting healing.
guest inclusion chemistry between α-CD and PEGMA 6.3. Supramolecular hydrogels for biosensing and
side chains in an aqueous solution, Niu et al. were bioimaging applications
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able to electrostatically complex the materials, resulting Supramolecular hydrogels can also be used in bioimaging
in a physically crosslinked, strain-driven, temperature- and biosensing applications. 7,8,161 Bioimaging plays a
responsive, and self-healing injectable polymer that is crucial role in visualizing specific molecular pathways in
well-suited for wound healing applications. Similar to vivo, enabling the rapid visualization of complex biological
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this work, Zheng et al. postulated the treatment of skin processes at the molecular level, such as cancer diagnosis
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burns using a host–guest supramolecular chemistry-based and therapy. 162,163 Supramolecular polymer hydrogel-
gelatin hydrogel filled with resveratrol (Res) and histatin-1 based bioimaging probes hold great promise for the
(His-1). diagnosis of cancer due to their smart responsiveness to
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Zhai et al. formulated a supramolecular hydrogel physiological stimuli, biodegradability, biocompatibility,
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that facilitates rapid hemostasis and efficient wound and 3D crosslinked structure. These probes, such as
healing. The hydrogel was formed with a cell adhesive supramolecular nanohydrogels, have been successfully
peptide (Pept-1) and alginate, and it was mechanically utilized as carriers for versatile bioimaging agents,
stable and aided wound healing without any growth facilitating both in vivo and in vitro bioimaging for several
factors. The hydrogel’s dense nanofibrillar structure, applications, including lymph node trafficking, tumor
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which was created through metal chelation-mediated targeting, and simultaneous delivery of therapeutic agents
co-assembly, and its electrostatic interactions effectively and imaging probes. 7,164
increased mechanical stability. Additionally, the hydrogel Biosensors integrate components for signal
was able to reduce bleeding without any hemolytic transduction and biomolecule recognition and have
effects and increase the rate of cell adhesion and emerged as valuable tools for the rapid and convenient
migration when used as wound dressing. Preman et al. detection of disease-related biomarkers. Supramolecular
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created a temperature-pH dual-responsive, degradable hydrogels, with their high biocompatibility and
supramolecular gel structure based on sodium responsive behavior to biological stimuli, hold great
alginate/poly(N-vinyl caprolactam) (AG/PVCL) and potential for biosensor applications. 165,166 They have been
tannic acid to speed up wound healing. Free radical utilized to construct optical and mechanical sensors
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polymerization was used to form the hydrogel scaffold, capable of detecting various bio-relevant molecules or
which was then crosslinked chemically and ionically. species, including cancer cells and bacteria. Additionally,
Through this method, tannic acid was able to strengthen supramolecular hydrogel-based biosensors have been
the crosslinking and mechanical toughness of the gel by developed for naked-eye detection, offering portable and
securing polymer chains through multiple interactions user-friendly solutions for biomedical and environmental
with their polyphenol arm. The hydrogel effectively applications, such as detecting ultralow concentrations of
regulated the release of tannic acid under physiological analytes. These advances in supramolecular hydrogel-
conditions and demonstrated capabilities to scavenge based biosensors contribute to the development of rapid,
free radicals, reduce inflammation, inhibit microbial sensitive, and cost-effective diagnostic systems. 7,8,167
growth, and promote cell proliferation. Recently, a gastric
environment-adaptive supramolecular self-healing 7. Challenges and future research in
hydrogel with ABA triblock polymer was reported with supramolecular synthesis and applications
outstanding anti-biofouling properties, which promises
better internal wound healing and reduces post-operative Supramolecular synthesis involves the non-covalent
complications in surgery. The hydrogel assembly interactions that assemble molecular monomers to create
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was made up of pH-sensitive acryloyl-6-aminocaproic larger functional structures, thereby presenting both
acid (A6ACA) moieties that were randomly integrated exciting opportunities and unique challenges. Achieving
into the terminal poly(N-isopropylacrylamide) precise control over the desired supramolecular structures

Volume 10 Issue 3 (2024) 27 doi: 10.36922/ijb.3223