Table 2 Cartilage-specific targeting ligands for stem cell delivery

Cartilage penetrating cationic peptide (CPC)

Fixed charge density (FCD) of cartilage

Rapid penetration in full cartilage, high absorption, and 7-day retention of CPC + 14

[78]

Supercharged green fluorescent proteins (GFPs)

Cartilage

Rapid transport into full-thickness cartilage and chondrocyte

[79]

CDP-11R

Cartilage

Accumulation in the cartilage after systemic intravenous injection; alleviation 0f joint inflammation and off-target toxicity

[73]

CBP peptide: LRELHLNNNC

Collagens

Targeting the extracellular matrix of inflamed tissues

[80]

PIGF2_123–144

ECM, collagen type II

Improved cartilage adhesion of MSCs

[74,75,76]

CAP peptide: DWRVIIPPRPSA

Chondrocytes

Plasmid DNA and exosome target delivery

[69,70,71]

Aggrecan-binding peptides peptide: RLDPTSYLRTFW, HDSQLEALIKFM

Aggrecan

Binding to chondrocytes and extracellular matrix

[72]

Type II collagen binding peptide: WYRGRL

Collagen type 2 (CII)

Deep zone retention, increased half-life and retention in the cartilage

[77, 81,82,83]

P15-1 peptide: STMMSRSHKTRSHHV

Hyaluronan (HA)

Inhibition of chondrocytes inflammation

[84]

Monoclonal antibody (mAbCII)

Collagen type 2

Enhanced collagen II binding and MMP-13 siRNA delivery for OA therapy

[85]

Avimer M26

Collagen II

Enhanced cartilage retention time

[86]

Multi-arm Avidin (mAv)

Aggrecan-associated glycosaminoglycans (GAGs)

Penetration through the full thickness of cartilage

[87, 88]