8-arm PEG (MW ~ 40 kDa) was purchased from JenKem Technology USA (Allen, TX, USA). Linear PEG (MW ~ 1.5 kDa) was purchased from Sigma-Aldrich USA (St. Louis, MO, USA). RGD peptide (CRGDS) was purchased from Bio Basic, Inc (Amherst, NY, USA). Sodium hyaluronate (HA) (MW ~ 20–40 kDa) was purchased from Lifecore Biomedical (Chaska, MN, USA). MMP-degradable peptide (CGPQGIWGQC) was purchased from GenScript (Piscataway, NJ, USA). 8-arm PEG-norbornene (PEG-NB) and Linear PEG-dithiol (PEG-SH) were synthesized as previously reported.19 (link),20 (link) Thiolated sodium hyaluronate (HA-SH) was synthesized as previously reported.21 (link) All other reagents were obtained from Fisher Scientific (Pittsburgh, PA, USA) unless otherwise noted.