Cryotemplation for the rapid fabrication of porous, patternable photopolymerized hydrogels

Thomas, Adrian; Shea, Lonnie D.

doi:10.1039/c4tb00585f

Cited by 13 publications

(11 citation statements)

References 80 publications

(127 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Porous PEG sponges were fabricated as done previously [28]. PEG-acrylate (4 arm, 20,000 Da; Laysan biomaterials; 10% w/v) was dissolved into PBS with photoinitiator (Irgacure 2959, Ciba; 0.5% w/v), frozen for 16 hours at −20 °C and then exposed while frozen to UV light (365 nm, 50 mW/cm 2 ; 2 min).…”

Section: Methodsmentioning

confidence: 99%

Sponge-mediated lentivirus delivery to acute and chronic spinal cord injuries

Thomas

Palma

Shea

2015

Journal of Controlled Release

Self Cite

View full text Add to dashboard Cite

The environment within the spinal cord after injury, which changes in the progression from the acute to chronic stages, limits the extent of regeneration. The delivery of inductive factors to promote regeneration following spinal cord injury has been promising, yet, few strategies are have are versatile to allow delivery during acute or chronic injury that would facilitate screening of candidate therapies. This report investigates the intrathecal delivery of lentiviruses for long-term expression of regenerative factors. Lentivirus-filled sponges were inserted into the intrathecal space surrounding the spinal cord, with transgene expression observed within multiple cell types that persists for 12 weeks for both intact and injured spinal cord, without any apparent damage to the spinal cord tissue. Sponges loaded with lentivirus encoding for Sonic hedgehog (Shh) were investigated for acute (delivered at 0 weeks) and chronic (at 4 weeks) injuries, and for multiple locations relative to the injury. In an acute model, sponges placed directly above the injury increased oligodendrocyte and decreased astrocyte presence. Sponges placed caudal to the injury had reduced impact on oligodendrocytes and astrocytes in the injury. In a chronic model, sponges increased oligodendrocyte and decreased astrocyte presence. Furthermore, the effect of Shh was shown to be mediated in part by reduction of Bmp signaling, monitored with an Msx2-sensitive reporter vector. The implantation of lentivirus-loaded biomaterials intrathecally provides the opportunity to induce the expression of a factor at a specified time without entering the spinal cord, and has the potential to promote gene delivery within the spinal cord, which can influence the extent of regeneration.

show abstract

Section: Methodsmentioning

confidence: 99%

Sponge-mediated lentivirus delivery to acute and chronic spinal cord injuries

Thomas

Palma

Shea

2015

Journal of Controlled Release

Self Cite

View full text Add to dashboard Cite

show abstract

“…For example, Inci et al prepared a gelatin cryogel crosslinked with oxidized dextran that displayed highly interconnected pores and a highly elastic nature, [68] while Thomas and Shea prepared poly ethylene glycol (PEG) hydrogels using cryotemplated photopolymerization that also demonstrated evidence of high pore interconnectivity. [69] In this way, cryogelation preserves the general advantages of porogenbased templating techniques while at least partially addressing the challenges of interconnectivity and template removal that limit the use of conventional porogens. The subzero temperature processing limits the application of cryogelation in some applications, particularly in conjunction with potential cell loading for tissue engineering applications.…”

Section: Cryogelationmentioning

confidence: 99%

Structured Macroporous Hydrogels: Progress, Challenges, and Opportunities

Hoare

2017

Adv Healthcare Materials

178

168

View full text Add to dashboard Cite

Structured macroporous hydrogels that have controllable porosities on both the nanoscale and the microscale offer both the swelling and interfacial properties of bulk hydrogels as well as the transport properties of “hard” macroporous materials. While a variety of techniques such as solvent casting, freeze drying, gas foaming, and phase separation have been developed to fabricate structured macroporous hydrogels, the typically weak mechanics and isotropic pore structures achieved as well as the required use of solvent/additives in the preparation process all limit the potential applications of these materials, particularly in biomedical contexts. This review highlights recent developments in the field of structured macroporous hydrogels aiming to increase network strength, create anisotropy and directionality within the networks, and utilize solvent‐free or additive‐free fabrication methods. Such functional materials are well suited for not only biomedical applications like tissue engineering and drug delivery but also selective filtration, environmental sorption, and the physical templating of secondary networks.

show abstract

“…While many methods exist for adjusting bulk porosity of photopolymerized hydrogels pre‐synthesis (monomer/macromer length, weight percent, photoinitiator type and concentration, light intensity and exposure time), or mechanically during synthesis, few exist for locally adjusting porosity post‐synthesis, especially in specific 3D geometries. Laser‐based hydrogel degradation provides enhanced control over local porosity within the desired 3D geometries, which could be useful in directing transport within on‐a‐chip devices.…”

mentioning

confidence: 99%