Skip to main content

Injectable, Hyaluronic Acid-Based Scaffolds with Macroporous Architecture for Gene Delivery

Abstract

Introduction

Biomaterials can provide localized reservoirs for controlled release of therapeutic biomolecules and drugs for applications in tissue engineering and regenerative medicine. As carriers of gene-based therapies, biomaterial scaffolds can improve efficiency and delivery-site localization of transgene expression. Controlled delivery of gene therapy vectors from scaffolds requires cell-scale macropores to facilitate rapid host cell infiltration. Recently, advanced methods have been developed to form injectable scaffolds containing cell-scale macropores. However, relative efficacy of in vivo gene delivery from scaffolds formulated using these general approaches has not been previously investigated. Using two of these methods, we fabricated scaffolds based on hyaluronic acid (HA) and compared how their unique, macroporous architectures affected their respective abilities to deliver transgenes via lentiviral vectors in vivo.

Methods

Three types of scaffolds—nanoporous HA hydrogels (NP-HA), annealed HA microparticles (HA-MP) and nanoporous HA hydrogels containing protease-degradable poly(ethylene glycol) (PEG) microparticles as sacrificial porogens (PEG-MP)—were loaded with lentiviral particles encoding reporter transgenes and injected into mouse mammary fat. Scaffolds were evaluated for their ability to induce rapid infiltration of host cells and subsequent transgene expression.

Results

Cell densities in scaffolds, distances into which cells penetrated scaffolds, and transgene expression levels significantly increased with delivery from HA-MP, compared to NP-HA and PEG-MP, scaffolds. Nearly 8-fold greater cell densities and up to 16-fold greater transgene expression levels were found in HA-MP, over NP-HA, scaffolds. Cell profiling revealed that within HA-MP scaffolds, macrophages (F4/80+), fibroblasts (ERTR7+) and endothelial cells (CD31+) were each present and expressed delivered transgene.

Conclusions

Results demonstrate that injectable scaffolds containing cell-scale macropores in an open, interconnected architecture support rapid host cell infiltration to improve efficiency of biomaterial-mediated gene delivery.

This is a preview of subscription content, access via your institution.

Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6

Abbreviations

HA:

Hyaluronic acid

HA-SH:

Thiolated hyaluronic acid

PEG:

Poly(ethylene glycol)

FLuc:

Firefly luciferase

FLuc-LV:

Firefly luciferase encoding lentivirus

PEG-VS:

Vinyl sulfone-terminated poly(ethylene glycol)

PEG-mal:

Maleimide-terminated poly(ethylene glycol)

DTT:

Dithiothreitol

References

  1. 1.

    Angulo-Jaramillo, R., J.-P. Vandervaere, S. Roulier, J.-L. Thony, J.-P. Gaudet, and M. Vauclin. Field measurement of soil surface hydraulic properties by disc and ring infiltrometers: A review and recent developments. Soil Tillage Res. 55:1–29, 2000.

    Article  Google Scholar 

  2. 2.

    Baier Leach, J., K. A. Bivens, C. W. Patrick, Jr, and C. E. Schmidt. Photocrosslinked hyaluronic acid hydrogels: natural, biodegradable tissue engineering scaffolds. Biotechnol. Bioeng. 82:578–589, 2003.

    Article  Google Scholar 

  3. 3.

    Baranski, J. D., et al. Geometric control of vascular networks to enhance engineered tissue integration and function. Proc. Natl. Acad. Sci. 110:7586–7591, 2013.

    Article  Google Scholar 

  4. 4.

    Bencherif, S. A., et al. Injectable preformed scaffolds with shape-memory properties. Proc. Natl. Acad. Sci. USA 109:19590–19595, 2012.

    Article  Google Scholar 

  5. 5.

    Bernabé, B. P., S. Shin, P. D. Rios, L. J. Broadbelt, L. D. Shea, and S. K. Seidlits. Dynamic transcription factor activity networks in response to independently altered mechanical and adhesive microenvironmental cues. Integr. Biol. 8:844–860, 2016.

    Article  Google Scholar 

  6. 6.

    Caldwell, A. S., G. T. Campbell, K. M. T. Shekiro, and K. S. Anseth. Clickable microgel scaffolds as platforms for 3D cell encapsulation. Adv. Healthc. Mater. 6:1700254, 2017.

    Article  Google Scholar 

  7. 7.

    Cao, Q., et al. Renal F4/80+CD11c+ mononuclear phagocytes display phenotypic and functional characteristics of macrophages in health and in adriamycin nephropathy. J. Am. Soc. Nephrol. 26:349–363, 2015.

    Article  Google Scholar 

  8. 8.

    Chau, Y., Y. Yu, L. Lau, and A. C. Lo. In vivo evaluation of hyaluronic acid based in situ hydrogel for prolonged release of Avastin by intravitreal injection. Invest. Ophthalmol. Vis. Sci. 55:5261, 2014.

    Google Scholar 

  9. 9.

    Chiu, Y.-C., J. C. Larson, A. Isom, and E. M. Brey. Generation of porous poly(ethylene glycol) hydrogels by salt leaching. Tissue Eng. C 16:905–912, 2010.

    Article  Google Scholar 

  10. 10.

    de Mello Coelho, V., et al. Fat-storing multilocular cells expressing CCR1 increase in the thymus with advancing age: potential role for CCR1 ligands on the differentiation and migration of preadipocytes. Int. J. Med. Sci. 7:1–14, 2009.

    Google Scholar 

  11. 11.

    Dull, T., et al. A third-generation lentivirus vector with a conditional packaging system. J. Virol. 72:8463–8471, 1998.

    Google Scholar 

  12. 12.

    Ellman, G. L. A colorimetric method for determining low concentrations of mercaptans. Arch. Biochem. Biophys. 74:443–450, 1958.

    Article  Google Scholar 

  13. 13.

    Ferreira, L. S., S. Gerecht, J. Fuller, H. F. Shieh, G. Vunjak-Novakovic, and R. Langer. Bioactive hydrogel scaffolds for controllable vascular differentiation of human embryonic stem cells. Biomaterials 28:2706–2717, 2007.

    Article  Google Scholar 

  14. 14.

    Gil-Ortega, M., et al. Native adipose stromal cells egress from adipose tissue in vivo: evidence during lymph node activation. Stem Cells Dayt. Ohio 31:1309–1320, 2013.

    Article  Google Scholar 

  15. 15.

    Gong, P., G. M. Harbers, and D. W. Grainger. Multi-technique comparison of immobilized and hybridized oligonucleotide surface density on commercial amine-reactive microarray slides. Anal. Chem. 78:2342–2351, 2006.

    Article  Google Scholar 

  16. 16.

    Gong, Y., Z. Ma, Q. Zhou, J. Li, C. Gao, and J. Shen. Poly(lactic acid) scaffold fabricated by gelatin particle leaching has good biocompatibility for chondrogenesis. J. Biomater. Sci. Polym. Ed. 19:207–221, 2008.

    Article  Google Scholar 

  17. 17.

    Gonzalez-Fernandez, T., E. G. Tierney, G. M. Cunniffe, F. J. O’Brien, and D. J. Kelly. Gene delivery of TGF-β3 and BMP2 in an MSC-laden alginate hydrogel for articular cartilage and endochondral bone tissue engineering. Tissue Eng. A 22:776–787, 2016.

    Article  Google Scholar 

  18. 18.

    Griffin, D. R., W. M. Weaver, P. O. Scumpia, D. Di Carlo, and T. Segura. Accelerated wound healing by injectable microporous gel scaffolds assembled from annealed building blocks. Nat. Mater. 14:737–744, 2015.

    Article  Google Scholar 

  19. 19.

    Han, L.-H., S. Yu, T. Wang, A. W. Behn, and F. Yang. Microribbon-like elastomers for fabricating macroporous and highly flexible scaffolds that support cell proliferation in 3D. Adv. Funct. Mater. 23:346–358, 2013.

    Article  Google Scholar 

  20. 20.

    Hiemstra, C., L. J. van der Aa, Z. Zhong, P. J. Dijkstra, and J. Feijen. Rapidly in situ-forming degradable hydrogels from dextran thiols through Michael addition. Biomacromolecules 8:1548–1556, 2007.

    Article  Google Scholar 

  21. 21.

    Higashikawa, F., and L.-J. Chang. Kinetic analyses of stability of simple and complex retroviral vectors. Virology 280:124–131, 2001.

    Article  Google Scholar 

  22. 22.

    Huebsch, N., et al. Matrix elasticity of void-forming hydrogels controls transplanted-stem-cell-mediated bone formation. Nat. Mater. 14:1269–1277, 2015.

    Article  Google Scholar 

  23. 23.

    Hwang, C. M., et al. Fabrication of three-dimensional porous cell-laden hydrogel for tissue engineering. Biofabrication 2:035003, 2010.

    Article  Google Scholar 

  24. 24.

    Ibrahim, S., Q. K. Kang, and A. Ramamurthi. The impact of hyaluronic acid oligomer content on physical, mechanical, and biologic properties of divinyl sulfone-crosslinked hyaluronic acid hydrogels. J. Biomed. Mater. Res. A 94A:355–370, 2010.

    Google Scholar 

  25. 25.

    Jain, A., Y.-T. Kim, R. J. McKeon, and R. V. Bellamkonda. In situ gelling hydrogels for conformal repair of spinal cord defects, and local delivery of BDNF after spinal cord injury. Biomaterials 27:497–504, 2006.

    Article  Google Scholar 

  26. 26.

    Johnson, P. J., A. Tatara, A. Shiu, and S. E. Sakiyama-Elbert. Controlled release of neurotrophin-3 and platelet-derived growth factor from fibrin scaffolds containing neural progenitor cells enhances survival and differentiation into neurons in a subacute model of SCI. Cell Transplant. 19:89–101, 2010.

    Article  Google Scholar 

  27. 27.

    Khazen, W., et al. Expression of macrophage-selective markers in human and rodent adipocytes. FEBS Lett. 579:5631–5634, 2005.

    Article  Google Scholar 

  28. 28.

    Kim, J. J., L. Hou, and N. F. Huang. Vascularization of three-dimensional engineered tissues for regenerative medicine applications. Acta Biomater. 41:17–26, 2016.

    Article  Google Scholar 

  29. 29.

    Kong, H. J., E. S. Kim, Y.-C. Huang, and D. J. Mooney. Design of biodegradable hydrogel for the local and sustained delivery of angiogenic plasmid DNA. Pharm. Res. 25:1230–1238, 2008.

    Article  Google Scholar 

  30. 30.

    Lamprecht, M. R., D. M. Sabatini, and A. E. Carpenter. Cell Profiler: free, versatile software for automated biological image analysis. BioTechniques 42:71–75, 2007.

    Article  Google Scholar 

  31. 31.

    Litwiniuk, M., A. Krejner, M. S. Speyrer, A. R. Gauto, and T. Grzela. Hyaluronic acid in inflammation and tissue regeneration. Wounds Compend. Clin. Res. Pract. 28:78–88, 2016.

    Google Scholar 

  32. 32.

    Liu, S., et al. Regulated viral BDNF delivery in combination with Schwann cells promotes axonal regeneration through capillary alginate hydrogels after spinal cord injury. Acta Biomater. 60:167–180, 2017.

    Article  Google Scholar 

  33. 33.

    Margul, D. J., et al. Reducing neuroinflammation by delivery of IL-10 encoding lentivirus from multiple-channel bridges. Bioeng. Transl. Med. 1:136–148, 2016.

    Article  Google Scholar 

  34. 34.

    Nikolaev, S. I., A. R. Gallyamov, G. V. Mamin, and Y. A. Chelyshev. Poly(ε-caprolactone) nerve conduit and local delivery of vegf and fgf2 genes stimulate neuroregeneration. Bull. Exp. Biol. Med. 157:155–158, 2014.

    Article  Google Scholar 

  35. 35.

    Patel, Z. S., S. Young, Y. Tabata, J. A. Jansen, M. E. K. Wong, and A. G. Mikos. Dual delivery of an angiogenic and an osteogenic growth factor for bone regeneration in a critical size defect model. Bone 43:931–940, 2008.

    Article  Google Scholar 

  36. 36.

    Perumcherry, S. R., K. P. Chennazhi, S. V. Nair, D. Menon, and R. Afeesh. A novel method for the fabrication of fibrin-based electrospun nanofibrous scaffold for tissue-engineering applications. Tissue Eng. C 17:1121–1130, 2011.

    Article  Google Scholar 

  37. 37.

    Peterson, A. W., D. J. Caldwell, A. Y. Rioja, R. R. Rao, A. J. Putnam, and J. P. Stegemann. Vasculogenesis and angiogenesis in modular collagen-fibrin microtissues. Biomater. Sci. 2:1497–1508, 2014.

    Article  Google Scholar 

  38. 38.

    Poursamar, S. A., J. Hatami, A. N. Lehner, C. L. da Silva, F. C. Ferreira, and A. P. M. Antunes. Gelatin porous scaffolds fabricated using a modified gas foaming technique: characterisation and cytotoxicity assessment. Mater. Sci. Eng. C 48:63–70, 2015.

    Article  Google Scholar 

  39. 39.

    Saraf, A., L. S. Baggett, R. M. Raphael, F. K. Kasper, and A. G. Mikos. Regulated non-viral gene delivery from coaxial electrospun fiber mesh scaffolds. J. Control. Release 143:95–103, 2010.

    Article  Google Scholar 

  40. 40.

    Schmidt, B. A., and V. Horsley. Intradermal adipocytes mediate fibroblast recruitment during skin wound healing. Dev. Camb. Engl. 140:1517–1527, 2013.

    Google Scholar 

  41. 41.

    Schulte, V. A., D. F. Alves, P. P. Dalton, M. Moeller, M. C. Lensen, and P. Mela. Microengineered PEG hydrogels: 3D scaffolds for guided cell growth. Macromol. Biosci. 13:562–572, 2013.

    Article  Google Scholar 

  42. 42.

    Sheikhi, A., et al. Microfluidic-enabled bottom-up hydrogels from annealable naturally-derived protein microbeads. Biomaterials 192:560–568, 2019.

    Article  Google Scholar 

  43. 43.

    Shepard, J. A., F. R. Virani, A. G. Goodman, T. D. Gossett, S. Shin, and L. D. Shea. Hydrogel macroporosity and the prolongation of transgene expression and the enhancement of angiogenesis. Biomaterials 33:7412–7421, 2012.

    Article  Google Scholar 

  44. 44.

    Shikanov, A., R. M. Smith, M. Xu, T. K. Woodruff, and L. D. Shea. Hydrogel network design using multifunctional macromers to coordinate tissue maturation in ovarian follicle culture. Biomaterials 32:2524–2531, 2011.

    Article  Google Scholar 

  45. 45.

    Sideris, E., et al. particle hydrogels based on hyaluronic acid building blocks. ACS Biomater. Sci. Eng. 2:2034–2041, 2016.

    Article  Google Scholar 

  46. 46.

    Skoumal, M., S. Seidlits, S. Shin, and L. Shea. Localized lentivirus delivery via peptide interactions. Biotechnol. Bioeng. 113:2033–2040, 2016.

    Article  Google Scholar 

  47. 47.

    Sokic, S., M. Christenson, J. Larson, and G. Papavasiliou. In situ generation of cell-laden porous MMP-sensitive PEGDA hydrogels by gelatin leaching. Macromol. Biosci. 14:731–739, 2014.

    Article  Google Scholar 

  48. 48.

    Thomas, A. M., and L. D. Shea. Polysaccharide-modified scaffolds for controlled lentivirus delivery in vitro and after spinal cord injury. J. Control. Release 170:421–429, 2013.

    Article  Google Scholar 

  49. 49.

    Thrailkill, K., G. Cockrell, P. Simpson, C. Moreau, J. Fowlkes, and R. C. Bunn. Physiological matrix metalloproteinase (MMP) concentrations: comparison of serum and plasma specimens. Clin. Chem. Lab. Med. CCLM FESCC 44:503–504, 2006.

    Google Scholar 

  50. 50.

    Tokatlian, T., C. Cam, and T. Segura. Non-viral DNA delivery from porous hyaluronic acid hydrogels in mice. Biomaterials 35:825–835, 2014.

    Article  Google Scholar 

  51. 51.

    Tremblay, P.-L., V. Hudon, F. Berthod, L. Germain, and F. A. Auger. Inosculation of tissue-engineered capillaries with the host’s vasculature in a reconstructed skin transplanted on mice. Am. J. Transplant. 5:1002–1010, 2005.

    Article  Google Scholar 

  52. 52.

    Truong, N. F., et al. Microporous annealed particle hydrogel stiffness, void space size, and adhesion properties impact cell proliferation, cell spreading, and gene transfer. Acta Biomater. 94:160–172, 2019.

    Article  Google Scholar 

  53. 53.

    Truong, N. F., S. C. Lesher-Pérez, E. Kurt, and T. Segura. Pathways governing polyethylenimine polyplex transfection in microporous annealed particle scaffolds. Bioconjug. Chem. 30:476–486, 2019.

    Article  Google Scholar 

  54. 54.

    Wang, L., J. Shansky, C. Borselli, D. Mooney, and H. Vandenburgh. Design and fabrication of a biodegradable, covalently crosslinked shape-memory alginate scaffold for cell and growth factor delivery. Tissue Eng. A 18:2000–2007, 2012.

    Article  Google Scholar 

  55. 55.

    Wood, M. Simple methods for estimating confidence levels, or tentative probabilities, for hypotheses instead of P values, 2017 [cited 2019 Feb 12]. http://arxiv.org/abs/1702.03129.

  56. 56.

    Xiao, W., et al. Brain-mimetic 3D culture platforms allow investigation of cooperative effects of extracellular matrix features on therapeutic resistance in glioblastoma. Cancer Res. 78:1358–1370, 2017.

    Article  Google Scholar 

  57. 57.

    Yang, C.-Y., et al. Biocompatibility of amphiphilic diblock copolypeptide hydrogels in the central nervous system. Biomaterials 30:2881–2898, 2009.

    Article  Google Scholar 

  58. 58.

    Zhang, W., et al. Vascularization of hollow channel-modified porous silk scaffolds with endothelial cells for tissue regeneration. Biomaterials 56:68–77, 2015.

    Article  Google Scholar 

  59. 59.

    Zhou, Y., W. Nie, J. Zhao, and X. Yuan. Rapidly in situ forming adhesive hydrogel based on a PEG-maleimide modified polypeptide through Michael addition. J. Mater. Sci. Mater. Med. 24:2277–2286, 2013.

    Article  Google Scholar 

Download references

Acknowledgments

The authors would like to acknowledge funding for this work from a National Science Foundation CAREER Award 1653730 (SKS), a UCLA Henry Samueli School of Engineering and Applied Sciences (HSSEAS) Faculty Research Grant (SKS) and a UCLA Faculty Career Development Award (SKS). We thank the UCLA Tissue Pathology Core Laboratory (TPCL) for cryosectioning and hematoxylin and eosin staining, the UCLA Crump Institute for Molecular Imaging for use of the IVIS imaging system, and the UCLA Molecular Instrumentation Center for use of proton NMR facilities. Confocal laser scanning microscopy was performed at the California NanoSystems Institute Advanced Light Microscopy/Spectroscopy Shared Resource Facility at UCLA, supported with funding from NIH-NCRR shared resources grant (CJX1-443835-WS-29646) and NSF Major Research Instrumentation Grant (CHE-0722519).

Conflict of interest

The authors declare that they have no conflicts of interest.

Ethical Standards

All animal studies were carried out in accordance with the NIH Guide for Care and Use of Laboratory Animals and approved by the UCLA Institutional Animal Care and Use Committee. No human studies were carried out by the authors for this article.

Author information

Affiliations

Authors

Corresponding author

Correspondence to Stephanie K. Seidlits.

Additional information

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Stephanie K. Seidlits is an Assistant Professor in the Department of Bioengineering at the University of California Los Angeles (UCLA). Dr. Seidlits received her Ph.D. in Biomedical Engineering from the University of Texas at Austin in 2010. Under the mentorship of Dr. Christine Schmidt and Dr. Jason Shear, her dissertation research focused on developing biomaterial-based strategies to promote nerve regeneration. Dr. Seidlits received a National Science Foundation (NSF) Integrated Graduate Education and Research Trainee (IGERT) Fellowship and a Scholar Award from the Philanthropic Education Organization (PEO). Dr. Seidlits then completed a post-doctoral fellowship at Northwestern University under the mentorship of Dr. Lonnie Shea, where she worked on several projects including development of biomaterial scaffolds with gene delivery capabilities for spinal cord injury repair and high-throughput arrays for monitoring dynamic activities transcription factors. During this time, she received the Rice University Outstanding Bioengineering Undergraduate Alumna Award, Northwestern University Institute for BioNanotechnology in Medicine-Baxter Early Career Award and a National Institutes of Health (NIH) F32 Ruth L. Kirchstein National Research Service Award (NRSA) for Post-Doctoral Training under the co-mentorship of Dr. Lonnie Shea and Dr. Aileen Anderson. Dr. Seidlits started her independent lab at UCLA in 2014, where her research uses biomaterial platforms to better understand the mechanisms underlying dysfunction and disease in central nervous system tissues and ultimately to develop new therapies. She has received an NSF CAREER Award, a UCLA Hellman Fellow Award, an American Brain Tumor Association Discovery Award and the 2019 Society for Biomaterials Young Investigator Award.

figurea

This article is part of the CMBE 2019 Young Innovators special issue.

Associate Editor Stephanie Michelle Willerth oversaw the review of this article.

Electronic supplementary material

Below is the link to the electronic supplementary material.

12195_2019_593_MOESM1_ESM.tif

Figure S1 Schematics of FITC-dextran incubation and confocal reconstruction of scaffolds (A) and hydraulic conductivity (B) experiments. Scaffolds were incubated in PBS containing high molecular weight FITC-dextran before imaging by confocal microscopy. Confocal stacks were taken near the surface of the scaffolds and imaged to a depth of 200 µm (A). Hydraulic conductivity was measured by forming scaffolds on top of a permeable membrane within a custom 3D printed device. PBS was placed on top of the scaffolds and the change in height of PBS was measured before and after at least 3 hours of incubation (B). (TIFF 4181 kb)

12195_2019_593_MOESM2_ESM.tif

Figure S2 Size distributions for microparticles produced by water-in-oil emulsion. PEG-MPs (A) are notably smaller and have a tighter distribution than HA-MPs (B) with a mean diameter of 20 ± 9 µm compared to that of 42 µm ± 23 µm for HA-MPs (C). Microparticle size distributions were assessed across three different batches and at least 500 microparticles of each type were cumulatively measured. Scale bars = 50 µm (TIFF 72170 kb)

12195_2019_593_MOESM3_ESM.tif

Figure S3. Rheological testing of NP-HA, PEG-MP, and HA-MP scaffolds. Rheological testing of NP-HA, PEG-MP, and HA-MP scaffolds show non-significant differences in storage moduli of NP-HA and HA-MP scaffolds. PEG-MP scaffolds had significantly greater moduli than either NP-HA or HA-MP scaffolds. Error bars represent standard deviation (*p<0.05, n=5, Kruskal Wallis test). (TIFF 21524 kb)

12195_2019_593_MOESM4_ESM.tif

Figure S4. Nuclei density at scaffold centers were measured at the radial center of scaffolds, and at least three sections per scaffolds were used for analysis. Immunostained tissue sections were imaged for nuclei (A, B), and cell density was calculated using thresholding and object analysis in CellProfiler to obtain cell counts over the section (C, D). Objects outlined in green are considered positive nuclei, whereas objects outlined in purple are excluded for not meeting size criteria. Scale bars = 500 µm (A, C) or 100 µm (B, D). (TIFF 137176 kb)

12195_2019_593_MOESM5_ESM.tif

Figure S5. Densities of nuclei were measured through the scaffold boundary in radial sections. Measurements were performed in radial sections and analysis were performed based on nuclei stained area on three separate regions per image and three images per condition. Immunostained tissue sections were imaged for nuclei (A), thresholded, and nuclei area per scaffold area were quantified (B). Scaffolds are indicated within the dashed lines. Scale bars = 200 µm. (TIFF 63386 kb)

12195_2019_593_MOESM6_ESM.tif

Figure S6. Differences in viral load did not affect cell infiltration or types of infiltrating cells within scaffolds. Quantification of cell density within all scaffolds showed no significant difference depending on viral load (A). Similarly, immunostaining did not exhibit any notable differences (B). Scaffolds are indicated on the left-hand side of the dashed lines. (N = 4, Unpaired t-test with Welch's correction). Scale bars = 200 µm. (TIFF 90442 kb)

12195_2019_593_MOESM7_ESM.tif

Figure S7. Quantification of immunostaining expression. Expression was quantified for immunostained sections (A) by applying a mask (B) around the scaffold area, applying it to the F4/80, CD31, or ERTR7 immunostained image (C), and quantifying staining density using CellProfiler software. Scaffolds are indicated within the dashed lines. Scale bars = 200 µm. (TIFF 116557 kb)

Supplementary material 8 (EPS 547 kb)

Supplementary material 9 (EPS 642 kb)

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Ehsanipour, A., Nguyen, T., Aboufadel, T. et al. Injectable, Hyaluronic Acid-Based Scaffolds with Macroporous Architecture for Gene Delivery. Cel. Mol. Bioeng. 12, 399–413 (2019). https://doi.org/10.1007/s12195-019-00593-0

Download citation

Keywords

  • Gene therapy
  • Tissue engineering
  • Injectable scaffold
  • Lentivirus