Effect of gel porosity and stiffness on culture of HepG2 cells encapsulated in gelatin methacrylate hydrogels

Abstract

Owing to in vivo applications, use of biodegradable three dimensional matrices to form implantable tissue constructs has increased in recent times. Gelatin methacrylate gel (GelMA) is one such versatile matrix compatible for cell culture and has potential of in vivo implantation. Physical and mechanical properties of these hydrogels are extremely crucial in modulating their rigidity, biodegradability and cellular compatibility. The present study involves testing stiffness and porosity of GelMA at high and low methacrylation degrees and at different concentrations of prepolymer and itseffect on viability and proliferation of HepG2 cells cultured encapsulated in GelMA. Stiffness was found to be directly proportional whereas porosity was found to be inversely related to degree of methacrylation and concentration of GelMA pre-polymer. Softer gel with greater porosity was found to be favorable for proliferation of cells encapsulated in the gel. In order to achieve stable implantable construct, it is important to fi ne tune its physical properties such as stiffness and porosity since both these parameters are responsible for governing culture of cells encapsulated within the gel matrix and the present study will be helpful in modulating these properties of GelMA as per the intended application.

Rapid 3D bioprinting of decellularized extracellular matrix with regionally varied mechanical properties and biomimetic microarchitecture

“…However, a decrease in HepG2 cell viability on day 3 and 7 of culture with considerably smaller spheroid size indicated that there was significant growth restriction on HepG2 cells when embedded in dECM-based scaffolds with a stiffness similar to cirrhotic liver. These findings are consistent with literature reports on reduced viability and growth in cancer cells cultured in stiff 3D hydrogels [9,36]. A further evaluation on the gene expression confirmed these results as attributed by the lower levels of the proliferation marker MKI67 , ALB , and AFP expression coupled with higher levels of the apoptosis marker CASP8 .…”

“…Traditional approaches to study HCC progression involved simply regulating 2D substrate stiffness, which, however, is not representative of the 3D mechanical environment in native liver and therefore could incur results inconsistent with those from 3D approaches [7–11]. Current studies examining the liver mechanical properties with 3D matrix models, however, do not reflect the clinically reported stiffness range and the microarchitecture of cirrhotic liver and thus provide less insightful results in understanding HCC progression under diseased conditions [9,12]. In addition to the importance of a relevant 3D mechanical environment, the biomaterial used to study cancer progression has also been shown to play an important role in regulating cancer growth and proliferation [13].…”

“…In addition to the importance of a relevant 3D mechanical environment, the biomaterial used to study cancer progression has also been shown to play an important role in regulating cancer growth and proliferation [13]. Current hydrogel matrices used to modulate stiffness, including alginate and gelatin [9,12], lack the biochemical cues inherent in the native liver ECM. Therefore, a biomimetic platform combining liver ECM as a tissue-specific biomaterial and a 3D mechanical environment with tissue-scale organization relevant to diseased liver is critical in studying the biomechanical contributions of the cirrhotic environment on HCC growth and invasion.…”

Bioinks for Space Missions: The Influence of Long‐Term Storage of Alginate‐Methylcellulose‐Based Bioinks on Printability as well as Cell Viability and Function

“…In contrast, for the HepG2-laden constructs of the control group W0, a strong increase of both, the DNA content and the LDH activity, was observed over the cultivation period of 14 days, indicating cell proliferation and high metabolic activity of the cells within the Plasma-Alg-MC. This is in line with our previous study [22] and can be attributed to the fact that hepatic cells prefer and are better adapted to soft hydrogels [56] due to their natural microenvironment. [22,56] Interestingly, despite the good performance of the HepG2 in the control group W0, the most dramatic effect of cold storage was observed for these cells: Whereas on day 1 after printing, the cell numbers in the storage groups W1-W4 were comparable to the control group W0, very low cell numbers were detected on day 7 and 14 of cultivation.…”

Biopolymer/Glycopolypeptide‐Blended Scaffolds: Synthesis, Characterization and Cellular Interactions

“…Natural biopolymers such as chitosan and gelatin have been extensively used to fabricate 3D-hydrogels, which have shown promise as scaffolds for several soft tissue engineering applications including liver tissues. [1,5,7,11,14,17,18,[27][28][29] For hepatocytes and hepatic cell lines that are presenti nl iver tissues, the spheroid morphology is critical towards maintaining high liver-specific functions. [30] However,t he trans-differentiation of hepatocytes into fibroblasts limits the culturingo fh epatocytes and still remains ac hallenge.…”