Designing degradable hydrogels is complicated by the structural and temporal complexities of the gel and evolving tissue. A major challenge is to create scaffolds with sufficient mechanical properties to restore initial function while simultaneously controlling temporal changes in the gel structure to facilitate tissue formation. Poly(ethylene glycol) was used in this work, to form biodegradable poly(ethylene glycol)-based hydrogels with hydrolyzable poly-l-lactide segments in the backbone. Non-degradable poly(ethylene glycol) was also introduced in the formulation to obtain control of the degradation profile that encompasses cell growth and new tissue formation. The dependence on polymer composition was observed by higher degradation profiles and decreased mechanical properties as the content of degradable segments was increased in the formulation. Based on in vitro tests, no toxicity of extracts or biomaterial in direct contact with human adipose tissue stem cells was observed, and the ultraviolet light treatment did not affect the proliferation capacity of the cells.
LeeJCuddihyMJKotovNA. Three-dimensional cell culture matrices: state of the art. Tiss Eng Part B Rev2008; 14: 61–86.
2.
RinkiKDuttaPKHuntAJ. Chitosan aerogels exhibiting high surface area for biomedical application: preparation, characterization, and antibacterial study. Int J Polym Mater Polym Biomater2011; 60: 988–999.
3.
HanJWangKYangD. Photo-polymerization of methacrylated chitosan/PNIPAAm hybrid dual-sensitive hydrogels as carrier for drug delivery. Int J Biol Macromol2009; 44: 229–235.
4.
WangXHeKZhangW. Optimizing the fabrication processes for manufacturing a hybrid hierarchical polyurethane–cell/hydrogel construct. J Bioact Compat Polym2013; 28: 303–319.
5.
EraJEKumarA. Designing supermacroporous cryogels based on polyacrylonitrile and a polyacrylamide-chitosan semi-interpenetrating network. J Biomater Sci Polym Ed2009; 20: 877–902.
6.
ParkHTemenoffJSHollandT. Delivery of TGF-β1 and chondrocytes via injectable, biodegradable hydrogels for cartilage tissue engineering applications. Biomaterials2005; 26: 7095–7103.
7.
BaiYFangRZhangS. Self-cross-linkable hydrogels composed of partially oxidized alginate and gelatin for myocardial infarction repair. J Bioact Compat Polym2013; 28: 126–140.
8.
SolaroRAlderighiMBarsottiMC. Chemical–physical and in vivo evaluations of a self-assembling amphiphilic peptide as an injectable hydrogel scaffold for biomedical applications perspective. J Bioact Compat Polym2013; 28: 3–15.
9.
XiaoWLiuWSunJ. Ultrasonication and genipin cross-linking to prepare novel silk fibroin–gelatin composite hydrogel. J Bioact Compat Polym2012; 27: 327–341.
10.
SantoVEGomesMEReisRL. Encapsulation of adipose-derived stem cells and transforming growth factor-β1 in carrageenan-based hydrogels for cartilage tissue engineering. J Bioact Compat Polym2011; 26: 493–507.
WnekGEBowlinGL. Encyclopedia of biomaterials and biomedical engineering (ed WnekGEBowlinGL). 2nd ed.New York: Informa Health Care, 2008.
13.
DhoteVSkaalureSAkalpU. On the role of hydrogel structure and degradation in controlling the transport of cell-secreted matrix molecules for engineered cartilage. J Mech Behav Biomed Mater2013; 19: 61–74.
14.
LeeKYMooneyDJ. Hydrogels for tissue engineering. Chem Rev2001; 101: 1869–1879.
15.
PeppasNAKeysKBTorres-LugoM. Poly(ethylene glycol)-containing hydrogels in drug delivery. J Control Release1999; 62: 81–87.
16.
BryantSJAnsethKS. The effects of scaffold thickness on tissue engineered cartilage in photocrosslinked poly(ethylene oxide) hydrogels. Biomaterials2001; 22: 619–626.
17.
MartensPAnsethKS. Characterization of hydrogels formed from acrylate modified poly(vinyl alcohol) macromers. Polymer2000; 41: 7715–7722.
18.
JiangZHaoJYouY. Biodegradable and thermoreversible hydrogels of poly(ethylene glycol)-poly(ϵ-caprolactone-co-glycolide)-poly(ethylene glycol) aqueous solutions. J Biomed Mater Res A2008; 87: 45–51.
19.
JoSEngelPSMikosAG. Synthesis of poly(ethylene glycol)-tethered poly(propylene fumarate) and its modification with GRGD peptide. Polymer2000; 41: 7595–7604.
20.
ZhangJSkardalAPrestwichGD. Engineered extracellular matrices with cleavable crosslinkers for cell expansion and easy cell recovery. Biomaterials2008; 29: 4521–4531.
21.
SawhneyASPathakCPHubbellJA. Bioerodible hydrogels based on photopolymerized poly(ethylene glycol)-co-poly(.alpha.-hydroxy acid) diacrylate macromers. Macromolecules1993; 26: 581–587.
22.
IfkovitsJLBurdickJA. Photopolymerizable and degradable biomaterials for tissue engineering applications. Tissue Eng2007; 13: 2369–2385.
BryantSJBenderRJDurandKL. Encapsulating chondrocytes in degrading PEG hydrogels with high modulus: engineering gel structural changes to facilitate cartilaginous tissue production. Biotechnol Bioeng2004; 86: 747–755.
25.
LienSMKoLYHuangTJ. Effect of pore size on ECM secretion and cell growth in gelatin scaffold for articular cartilage tissue engineering. Acta Biomater2009; 5: 670–679.
AnnabiNNicholJWZhongX. Controlling the porosity and microarchitecture of hydrogels for tissue engineering. Tissue Eng Part B Rev2010; 16: 371–383.
28.
Saez-MartinezVAtorrasagastiGOlaldeB. Fabrication and characterization of macroporous poly(ethylene glycol) hydrogels generated by several types of porogens. Int J Polym Mater Polym Biomater2013; 62: 502–508.
29.
ZhuJ. Bioactive modification of poly(ethylene glycol) hydrogels for tissue engineering. Biomaterials2010; 31: 4639–4656.
30.
YoonJJSongSHLeeDS. Immobilization of cell adhesive RGD peptide onto the surface of highly porous biodegradable scaffolds fabricated by a gas foaming/salt leaching method. Biomaterials2004; 25: 5613–5620.
31.
MaxsonSLopezEAYooD. Concise review: role of mesenchymal stem cells in wound repair. Stem Cells Transl Med2012; 1: 142–149.
32.
BryantSJAnsethKS. Hydrogel properties influence ECM production by chondrocytes photoencapsulated in poly(ethylene glycol) hydrogels. J Biomed Mater Res2002; 59: 63–72.
33.
BurdickJAPetersonAJAnsethKS. Conversion and temperature profiles during the photoinitiated polymerization of thick orthopaedic biomaterials. Biomaterials2001; 22: 1779–1786.
34.
StuderKDeckerCBeckE. Thermal and photochemical curing of isocyanate and acrylate functionalized oligomers. Eur Polym J2005; 41: 157–167.
35.
ZukPAZhuMMizunoH. Multilineage cells from human adipose tissue: implications for cell-based therapies. Tissue Eng2001; 7: 211–226.
