Injectable, pore-forming hydrogels for materials-based cell therapies

Abstract

The invention provides compositions and methods to form pores in situ within hydrogels following hydrogel injection. Pores formed in situ via degradation of sacrificial porogens within the surrounding hydrogel facilitate recruitment or release of cells. Disclosed herein is a material that is not initially porous, but which becomes macroporous over time.

1 .- 25 . (canceled) 
     
     
         26 . A composition comprising a composite scaffold composition, wherein the composite scaffold composition:
 (i) is a polymeric scaffold composition   (ii) lacks macropores having a diameter of at least 20 μm;   (iii) comprises a crosslinked bulk hydrogel encapsulating sacrificial porogen hydrogel micro-beads having a diameter between about 20 μm and about 500 and   (iv) comprises sacrificial porogen hydrogel micro-beads at a density of between 50% to 80% of the overall volume of the composite polymeric composition, and that comprise oxidized alginate or a shorter polymer than said bulk hydrogel such that the sacrificial porogen hydrogel micro-beads degrade at least 10% faster than said bulk hydrogel in situ;   wherein upon administration to a subject the sacrificial porogen hydrogel micro-beads degrade in situ to form a network of macropores having a diameter between about 20 μm and about 500 μm in their place, and an intact hydrogel network which allows for the recruitment of cells into the scaffold in situ.   
     
     
         27 . The composition of  claim 26 , wherein said composite composition further comprises:
 (i) a chemokine;   (ii) a programming factor;   (iii) a tumor antigen;   (iv) a bioactive factor selected from the group consisting of vascular endothelial growth factor (VEGF), acidic fibroblast growth factor (aFGF), basic fibroblast growth factor (bFGF), placenta growth factor (PIGF), platelet derived growth factor (PDGF), leptin, hematopoietic growth factor (HGF), VEGF receptor-1 (VEGFR-1), VEGFR-2, a member of the bone morphogenetic protein (BMP) family, granulocyte/macrophage colony stimulating factor (GM-CSF), FMS-like tyrosine kinase 3 ligand (FIt3 ligand), hepatocyte growth factor, stromal derived factor 1 (SDF-1), insulin like growth factor (IGF), anti-VEGF antibody, anti-aFGF antibody, anti-bFGF antibody, anti-PIGF antibody, anti-leptin antibody, anti-HGF antibody, anti-VEGFR-1 antibody, antiVEGFR-2 antibody, anti-PDGF antibody, anti-BMP antibody, anti-FIt3 ligand, and anti-IGF antibody;   (v) a bioactive factor selected from the group consisting of BMP-2, BMP-4, and RunX;   (vi) a bioactive factor comprising MyoD; and/or   (vii) a bioactive factor comprising FGF.   
     
     
         28 . The composition of  claim 27 , wherein:
 (i) said chemokine comprises granulocyte/macrophage colony stimulating factor (GM-CSF); and/or   (ii) said programming factor comprises a condensed oligonucleotide, wherein said condensed oligonucleotide comprises CpG or plasmid DNA.   
     
     
         29 . The composition of  claim 26 , wherein said cells migrate into macropores of said composite composition in situ, wherein said cells comprise lymphocytes or antigen presenting cells, wherein said antigen presenting cells comprise dendritic cells. 
     
     
         30 . The composition of  claim 26 , wherein:
 (i) said sacrificial porogen hydrogel micro-beads comprise oxidized alginate;   (ii) said sacrificial porogen hydrogel micro-beads comprise 3-7.5% oxidized alginate;   (iii) said sacrificial porogen hydrogel micro-beads comprise alginate dialdehyde; or   (iv) said sacrificial porogen hydrogel micro-beads comprise 20 mg/mL oxidized alginate and 7.5 mg/mL unmodified alginate.   
     
     
         31 . The composition of  claim 26 , wherein said sacrificial porogen hydrogel micro-beads or said bulk hydrogel comprise an isolated cell, optionally wherein said isolated cell is a mesenchymal stem cell, a myoblast, a vascular progenitor cell, a differentiated cell derived from an embryonic stem cell or an induced pluripotent stem cell, an induced pluripotent cell, or a cell that was directly reprogrammed from a fibroblast to a differentiated state. 
     
     
         32 . The composition of  claim 26 , wherein:
 (i) said sacrificial porogen hydrogel micro-beads comprise an elastic modulus of between 20 kPa and 60 kPa;   (ii) said bulk hydrogel comprises a peptide comprising an amino acid sequence of PHSRN (SEQ ID NO: 1), DGEA (SEQ ID NO: 2), or RGD;   (iii) said bulk hydrogel comprises a density of RGD peptides from 2 to 10 peptides per alginate polymer chain; and/or   (iv) said bulk hydrogel comprises an initial elastic modulus of at least 40 kPa.   
     
     
         33 . The composition of  claim 26 , wherein:
 (i) said composite scaffold composition promotes bone or cartilage repair, regeneration, or formation;   (ii) said composite scaffold composition further comprises a bioactive factor selected from the group consisting of BMP-2, BMP-4, and RunX;   (iii) said sacrificial porogen hydrogel micro-beads or said bulk hydrogel comprise an isolated bone cell selected from the group consisting of an osteoblast, an osteocyte, an osteoclast, and an osteoprogenitor, optionally, wherein said isolated bone cell is an autologous or allogenic cell; and/or   (iv) said sacrificial porogen hydrogel micro-beads or said bulk hydrogel comprise an isolated cartilage cell, optionally, wherein said isolated cartilage cell comprises a chondroblast.   
     
     
         34 . The composition of  claim 26 , wherein:
 (i) said composite scaffold composition promotes muscle repair, regeneration, or formation;   (ii) said composite scaffold composition further comprises a bioactive factor, wherein said bioactive factor comprises MyoD; and/or   (iii) said sacrificial porogen hydrogel micro-beads or said bulk hydrogel comprise an isolated muscle cell selected from the group consisting of a skeletal muscle cell, a cardiac muscle cell, a smooth muscle cell, and a myoprogenitor cell, optionally, wherein said isolated muscle cell is an autologous or allogenic cell.   
     
     
         35 . The composition of  claim 26 , wherein:
 (i) said composite scaffold composition promotes skin repair, regeneration, or formation;   (ii) said composite scaffold composition further comprises a bioactive factor, optionally, wherein said bioactive factor comprises FGF; and/or   (iii) said sacrificial porogen hydrogel micro-beads or said bulk hydrogel comprise an isolated skin cell selected from the group consisting of a fibroblast, a dermal cell, an epidermal cell, and a dermal progenitor cell, optionally, wherein said isolated skin cell is an autologous cell or an allogeneic cell.   
     
     
         36 . The composition of  claim 26 , wherein sacrificial porogen hydrogel micro-beads are present at a density of 60% of the overall volume of the composite scaffold composition. 
     
     
         37 . The composition of  claim 30 , wherein:
 (i) at least 5% of said alginate is oxidized; and/or   (ii) said bulk hydrogel comprises unmodified alginate.   
     
     
         38 . The composition of  claim 26 , wherein:
 (i) said sacrificial porogen hydrogel micro-beads comprise an oxidized alginate polymer having a molecular weight from 5,000 to 500,000 Daltons (Da);   (ii) said bulk hydrogel comprises an alginate polysaccharide having a molecular weight from 5,000 to 500,000 Da;   (iii) said sacrificial porogen hydrogel microbeads comprise polymers with a molecular mass of approximately 50 kDa;   (iv) said bulk hydrogel comprises polymers with a molecular mass of approximately 250 kDa.   (v) dendritic cells are recruited into said macropores and programmed to be activated antigen-presenting dendritic cells to elicit an antitumor response;   (vi) said sacrificial porogen hydrogel micro-beads and said bulk hydrogel are biodegradable.   (vii) said macropores comprise macropores that are 50 μm to 500 μm in diameter;   (viii) said macropores comprise macropores that are 100 μm to 500 μm in diameter; and/or   (ix) said macropores comprise macropores that are 50 μm to 400 μm in diameter.   
     
     
         39 . The composition of  claim 26 , wherein:
 (i) said sacrificial porogen hydrogel micro-beads comprise oxidized alginate and said bulk hydrogel comprises oxidized alginate;   (ii) said bulk hydrogel comprises less oxidized alginate than said sacrificial porogen hydrogel micro-beads;   (iii) said sacrificial porogen hydrogel micro-beads comprise 3-7.5% oxidized alginate; and/or   (iv) said sacrificial porogen hydrogel micro-beads comprise a shorter alginate polymer than said bulk hydrogel.   
     
     
         40 . A method of deploying cells from a scaffold into tissues of a mammalian subject, comprising administering to a subject a composition of  claim 26 , and wherein said sacrificial porogen hydrogel micro-beads or said bulk hydrogel comprise an isolated cell. 
     
     
         41 . A method of recruiting cells into a scaffold in vivo, comprising administering to a subject a composition of  claim 26 .