Kevin E. Healy. University of California, Berkeley

Transcription

1 Bioinspired Approaches for Drug Delivery and Tissue Engineering Kevin E. Healy Departments of Materials Science and Engineering, and Bioengineering University of California, Berkeley

2 Drug Delivery Example: DaunoXome A Liposome Injection (FDA approved) single use vial for IV infusion Liposome composed of distearoylphosphatidylcholine and cholesterol (2:1 molar ratio) Drug: Daunorubicin (chemotherapy) distearoylphosphatidylcholine

3 MacroMed Technology: sol-gel formulations ABA triblock copolymer poly(d,l-lactide-co-glycolide)-block-poly(ethyleneglycol)-block-poly(d,l-lactide-co-glycolide) PLGA-PEG-PLGA p((dll-co-g)-b-eg-b-(dll-co-g)) Controlled delivery Solubilize of hydrophobic drugs Localized delivery, e.g., hgh Macromed, Inc. (

4 MacroMed Technology: sol-gel formulations ABA triblock copolymer p((dll-co-g)-b-eg-b-(dll-co-g))

5 Drug Delivery for Regenerative Medicine Mechanical properties (e.g. G*, G, G ) Plasmid Nanoparticle Antisense Oligos sirna Therapeutics Proteins Growth factor presentation Transcription Factors Antibodies Anti-Inflammatories Drug delivery (soluble and immobilized)

6 The Cell-Extracellular Matrix Niche is Complex with Myriad Signals Cell-matrix interactions control cell behavior and fate decisions Pollock, J., and Healy, K.E., Biomimetic and Bio-responsive Materials in Regenerative Medicine: Intelligent Materials for Healing Living Tissues, In Strategies in Regenerative Medicine, M. Santin (Ed.), Springer, 2009

7 Central Tenets in 3D Matrix Design Growth Factor Presentation Relevant material properties (E, G) Cell binding domains

8 Designing Materials to Direct Cell Fate Ligand Presentation & Receptor Clustering Material Architecture Material Mechanics Saha, K., et al., Current Opinion in Chemical Biology, 11 (4), (2007)

9 Bioinspired Materials Design Cell-binding domains can be incorporated into materials by a variety of methods A.) simple surface adsorption; B.) self-assembling monolayers; C.) grafting from polymer hydrogel; D.) incorporation as polymer backbone of a hydrogel; E.) amphiphile molecule adsorption; F.) surface grafting or modification; G.) grafted linear chains of semi-interpentrating network; and H.) grafting to interpenetrating network surface. Pollock, J., and Healy, K.E., Biomimetic and Bio-responsive Materials in Regenerative Medicine: Intelligent Materials for Healing Living Tissues, In Strategies in Regenerative Medicine, M. Santin (Ed.), Springer, 2009

10 Bioinspired Materials Design Growth factors or drugs can be incorporated into materials by a variety of methods (A) (B) (C) (D) (E) (F) Pollock, J., and Healy, K.E., Biomimetic and Bio-responsive Materials in Regenerative Medicine: Intelligent Materials for Healing Living Tissues, In Strategies in Regenerative Medicine, M. Santin (Ed.), Springer, 2009

11 Tunable Hydrogels for Regenerative Medicine Tunable Surface Coatings and 3D Matrices Mechanical properties Biological ligands Tissue adhesion Protease degradation Growth factor delivery Gene therapy vehicles Peptides for cell adhesion Growth factors for differentiation Mechanical properties (e.g. G*, G, G ) Peptide cross-links with MMP labile peptide sequence X = Gln-Pro-Gln-Gly-Leu-Ala-Lys-NH 2 Peptide sequence containing MMP-degradable sequence (MMP-2,-9, & 13) Kim, S.-Y., et al., Biomacromolecules, 4, (2003) Kim, S.-Y., et al., J. Biomed. Mater. Res., 75(1), 2005 Li, Y. et al., J. Biomed. Mater. Res. A, 79A (2006) Chung, E. et al., J. Biomed. Mater. Res. A, 79A (2006) Wall, S., et al, J. Biomed. Mater. Res. A, 1055 (2010)

12 Pollock, J., and Healy, K.E., Biomimetic and Bio-responsive Materials in Regenerative Medicine: Intelligent Materials for Healing Living Tissues, In Strategies in Regenerative Medicine, M. Santin (Ed.), Springer, 2009

13 Bioinspired ECMs for Regenerative Medicine Environmentally-responsive hydrogels p(nipaam-co-aac) Hydrogel Cells Room T ~ 22 C Water T ~ 40 C ph 7.4

14 Hypothesis Matrix Assisted Myocardium Stabilization (MAMS) Injection of a non-viable passive material will add mechanical support, reduce wall stress, improve ejection fraction, and halt progression of CHF Delivery of drugs & gene therapy agents will foster angiogenesis and stem cell proliferation Infarct Region Blockage Injected hydrogel or stem cells Angiogenesis Cell Proliferation Reduced Apoptosis

15 Wall, S., et al, Circulation, 114, 2627, 2006 Therapeutic Multiple Border Zone Injections

16 Matrix Assisted Myocardium Stabilization (MAMS) Murine Infarct Model Infarct Region Blockage Treatment Groups Saline Injection sipn Injection GFP(+) MSCs sipn + GFP(+) MSCs Matrigel + GFP(+) MSCs Injected hydrogel or stem cells Wall, S., et al, J. Biomed. Mater. Res. A, 1055 (2010) GFP-expressing MSCs + CD-90 +CD-71 +CD-117 -CD-34 - CD-45

17 Matrix Assisted Myocardium Stabilization (MAMS) Murine Infarct Model Treatment 1 hr after infarct sipn Injection Saline Injection Wall, S., et al, J. Biomed. Mater. Res. A, 1055 (2010)

18 Matrix Assisted Myocardium Stabilization (MAMS) Cardiac Function 6 weeks Post Treatment 55 Fractional Shortening (%) MI + Saline MI + sipn MI + BMSC MI + sipn/bmsc MI + Matrigel/BMSC Time (weeks) Wall, S., et al, J. Biomed. Mater. Res. A, 1055 (2010) *

19 Mulivalent Sonic Hedgehog (Shh) Presentation for Stem Cell Differentiation Shh-HyA conjugates may have enhanced activity due to differential avidity, stability, and/or internalization Patched Binding Site C-Terminal Cysteine residue added 6xHis Tag EK proteolytic site Proliferation VEGF isoforms N-Terminal Hydrophobic modifications Smo Ptc K Shh Ptc-Shh Ang1 Gli3A Gli3R (Ptc) in (Ptc-Shh) in x Ang2 ptc BMPs gli1 Gli1 Nucleus Wall, S., Bioconjugate Chemistry, 19, 806 (2008) Ho et al., J Biomed Mater Res A, 83A, 1200 (2007)

20 Mulivalent Sonic Hedgehog (Shh) Presentation for Stem Cell Differentiation D ~ 100 nm vs. Shh:HyA 22:1 7:1 Wall, S., Bioconjugate Chemistry, 19, 806 (2008) Shh-HA conjugates may have differential activity due to differential avidity, stability, and/or lack of internalization

21 Multivalency of Sonic Hedgehog Conjugated to Linear Polymer Chains Modulates Protein Potency Control Soluble Shh Multivalent Shh (14:1) Wall, S., Bioconjugate Chemistry, 19, 806 (2008)

22 Hyaluronic Acid Hydrogels for Regenerative Medicine

23 Growth Factor Retention in Hyaluronic Acid-Based Hydrogels Cumulative TGF β1 (%) Retention Release Time (days)

24 Cardiac Progenitor Cell Response to Hyaluronic Acid-Based Hydrogels HyA-PHT HyA-PH HyA-P HyA

25 Cardiac Progenitor Cell Response to Hyaluronic Acid-Based Hydrogels HyA-PHT HyA-PH HyA-P HyA 12 Days of Culture CD31 (above), LDL(lower) (red), Cell nuclei (blue)

26 Cardiac Progenitor Cell Response to Hyaluronic Acid-Based Hydrogels 380 µm RGD 250 µm RGD 120 µm RGD 850 Pa 170 Pa 15 Pa

27 Cardiac Progenitor Cell Response to Hyaluronic Acid-Based Hydrogels

28 Bioinspired Materials Design Growth factors or drugs can be incorporated into materials by a variety of methods (A) (B) (C) (D) (E) (F) Pollock, J., and Healy, K.E., Biomimetic and Bio-responsive Materials in Regenerative Medicine: Intelligent Materials for Healing Living Tissues, In Strategies in Regenerative Medicine, M. Santin (Ed.), Springer, 2009

29 Summary We have designed and synthesized materials that are tunable with respect to mechanical properties (e.g. G*) biological ligands ligand clustering protease degradation growth factor presentation These are robust materials for testing hypothesis addressing factors that regulate stem cell proliferation and fate determination in vitro tissue regeneration in vivo

30 Thank You This research was supported by Siebel Stem Cell Institute, NIH-NIGMS R01GM & NIH-NHLBI R01HL California Institute for Regenerative Medicine (CIRM) American Heart Association University of California, Berkeley Prof. Costas Grigoropoulos Prof. David Schaffer Raymond Schmidt, Ph.D. S-Y. Kim, Ph.D. Beth Irwin, Ph.D. Greg Harbers, Ph.D. Rohini Gupta, Ph.D. Naomi Kohen Jacob Pollock, Ph.D. San Francisco Prof. Michael Mann Prof. Mark Ratcliffe Prof. Julius Guccione Prof. Bruce Conklin Hojeong Jeon, Ph.D. Kris Saha, Ph.D. Sam Wall, Ph.D. Rohini Gupta, Ph.D. James Su, Ph.D. Ranee A. Stile, Ph.D. Ying Meng, Ph.D. Rush Medical University Prof. Rick Sumner Prof. Amarjit Virdi University of Massachusetts - Amhearst Prof. Ryan Hayward University of Washington Prof. David Castner & Laura Gamble Prof. Albert Folch Stanford University Prof. Joe Wu