Table 2 Summary of in vitro studies characteristics and outcomes

[16]

UCMSCs (human)

Articular cartilage

(human, healthy)

10⁹EVs/explant (14 days)

No changes in ECM content (proteoglycans/collagen)

[46]

ADSCs (human)

Articular cartilage

(human, OA, 38–54 y/o)

2.5 × 10⁹EVs/ml (40 h)

sEVs preconditioned with IL-1β have chondro-protective miRNA content

EVs penetrate in micromasses and cartilage explants (40 μm depth)

[39]

BMSCs vs. SFMSCs (horse)

Articular chondrocytes

(horse, healthy, 5–10 y/o)

IL-1β/TNF-α + 4 × 10⁹EVs (24 h)

Reduced MMP13 [qPCR] (BMSC-EVs only)

[17]

ADSCs (human)

Articular chondrocytes

(human, healthy)

5 × 10⁹EVs/mL (3 days)

Increased cell proliferation and migration and reduced apoptosis;

Increased COL1, COL2 [qPCR]

[25]

SMSCs (human)

Articular chondrocytes

(human, OA)

IL-1β + 10¹⁰EVs/ml (24–48 h)

Increased cell proliferation and migration and reduced apoptosis

Increased ACAN, COL2A1; reduced ADAMTS5 [Western blot]

[28]

UCMSCs (human)

Articular chondrocytes

(human, OA)

10 µg/ml (2–7 days)

No effect on cell proliferation (48 h)

No change in COL2; increased ACAN, RUNX2 [qPCR] (1 week)

[12]

BMSCs (human)

Articular chondrocytes

(human, OA)

IL-1α + 1 µg/ml EVs (16–48 h)

Internalization efficiency increases with IL-1α

Reduced IL8, IL8, COX2 at 16 h but no effect at 48 h

[31]^†

ADSCs (human)

Articular chondrocytes

(human, OA)

IL-1β + 10⁸EVs (24–72 h)

Increased cell proliferation and migration

Reduced MMPs, ADAMTS5; increased COL2 [qPCR]

Reduced MMPs [ELISA]

[14]

ADSCs (human)

Articular chondrocytes

(human, OA, 38–54 y/o)

Chondrogenesis + 2.5 × 10⁹EVs/ml (48 h)

EVs fully penetrate chondrocyte micromasses

EVs quickly penetrate the surface of cartilage explants

[23]

BMSCs (human)

Articular chondrocytes

(human, OA, 55–83 y/o)

EVs from 6 × 10⁴MSCs in 300 µl

Increased cell viability

EVs from 6 × 10⁶MSCs for 3 pellets

Increased SOX9, COL2, ACAN [qPCR] (21 days)

[19]

ADSCs (human)

Articular chondrocytes

(human, OA, 64 ± 13 y/o)

TNF-α + EVs from 10⁵ADSCs (3–6 days)

Increased cell proliferation

No changes in TNFα-induced MMP activity but reduced COL10 [Western blot]

[22]

BMSCs (human)

Articular chondrocytes

(human, OA, 66 ± 7 y/o)

IL-1β + 10 µg/ml EVs (24 h)

Increased cell proliferation and migration and reduced apoptosis

Increased COL2, SOX9, ACAN; reduced COLX, MMP13, IL6 [qPCR]

[15]

ADSCs (human)

Articular chondrocytes

(human, OA, 67 ± 5 y/o)

50,000 EVs/chondrocyte

ECM plays a crucial role in EV-cell interactions

Outcomes can vary significantly between 2D and 3D environments

[21]

BMSCs (human)

Articular chondrocytes

(human, OA, 67 ± 8 y/o)

IL-1β + 10 µg/ml EVs (24 h)

Increased cell proliferation and migration and reduced apoptosis

Increased COL2, SOX9, COMP; reduced COLX, MMP13, ALPL, IL1β [qPCR]

[24]

ADSCs (human)

Articular chondrocytes

(human, OA, 68 ± 8 y/o)

IL-1β + 7.2 × 10⁷EVs/mL (24 h)

Reduced oxidative stress

[32]

ADSCs (mouse)

Articular chondrocytes

(mouse, healthy, 4 weeks old)

TBHP + 10⁹EVs (24–48 h)

Increased cell proliferation

Reduced apoptosis and oxidative stress

Increased ACAN, COL2; reduced MMP13, ADAMTS5, IL-1β, TNF-α [qPCR]

[40]

BMSCs (mouse)

Articular chondrocytes

(mouse, healthy, 8 weeks old)

IL-1β + 100 µg/mL EVs (24 h)

Increased cell proliferation and migration and reduced apoptosis

Reduced TNF-α, IL-6 [ELISA]

[37]

UCMSCs (human)

Articular chondrocytes

(mouse, healthy, newborn)

Chondrogenesis + 10⁹EVs/mL (21 days)

Increased area of micromasses

Increased ACAN, COL2 [Western blot]

[66]

BMSCs (human)

Articular chondrocytes

(mouse, OA)

200 µg EVs

Increased cell proliferation and migration and reduced apoptosis

[44]

BMSCs (human)

Articular chondrocytes

(rabbit, healthy)

5 × 10⁸− 2 × 10⁹EVs/ml (24–48 h)

Increased cell proliferation and migration

Increased mitochondrial function

[26]

BMSCs (rat)

Articular chondrocytes

(rat, healthy)

150 µg/ml EVs (24 h)

Hypoxia enhances the release of sEVs from BMSCs and their uptake by chondrocytes

Increased cell proliferation and migration and reduced apoptosis

Increased COL2; reduced MMP13 [Western blot]

[42]

UCMSCs (human)

Articular chondrocytes

(rat, healthy)

IL-1β + 15 µg/ml EVs (24–72 h)

Increased cell proliferation and migration

[43]

ADSCs (rat)

Articular chondrocytes

(rat, healthy)

2 × 10⁹EVs/ml (20 µg/ml) (24–72 h)

Increased cell proliferation and migration and reduced apoptosis

[27]

BMSCs (human)

Articular chondrocytes

(rat, healthy, 4 weeks old)

IL-1β + 20 µg EVs (24–48 h)

Increased cell proliferation and migration and reduced apoptosis

[35]

UCMSCs (human)

Articular chondrocytes

(rat, healthy, 5 days old)

IL-1β + 5 × 10⁸EVs/ml (72 h)

Increased ACAN, COL2 [immunofluorescence]; Reduced MMP13 [Western blot]

[43]

ADSCs (rat)

Articular chondrocytes

(rat, healthy, 6–8 weeks old)

IL-1β + 50 µg/mL EVs (48–72 h)

Increased cell proliferation and migration and reduced apoptosis

Increased COL2, COL1, RUNX2, osteocalcin; reduced p53, IL-1β [qPCR/Western blot]

[38]

BMSCs (human)

Cell line C28/I2

(human costal cartilage, SV40LT)

IL-1β + 10 µg/ml EVs (24 h)

Increased cell proliferation and migration and reduced apoptosis

Reduced IL6; no changes in MMP13 [Western blot]

[41]

SMSCs (human)

Cell line SW1353

(human chondrosarcoma)

IL-1β + 10¹¹EVs/ml (24 + 6 hours)

Increased cell proliferation and reduced apoptosis (48 h)

Reduced TNF-α; increased IL-10 [ELISA]

[13]

ADSCs (human)

Costal chondrocytes

(human, healthy, pediatric patients)

15 µg/mL sEVs (72 h)

Increased cell proliferation (2D)

Increased COL1, COL2 (2D and 3D) [Western blot]

[67]

BMSCs vs. ADSCs (human)

Growth cartilage

(mouse, foetal)

0.5 µg/explant (7 days)

ADSC-EVs promote angiogenesis

BMSC-EVs promote chondrogenesis and growth plate organization

[33]

BMSCs (human)

Mandibular condylar chondrocytes

(rabbit, healthy)

IL-1 + 2–4 × 10⁸EVs (24 h)

Increased cell proliferation and migration

Increased SOX9, COL2 [qPCR/Western blot]

[36]

DFCs (rat)

Mandibular condylar chondrocytes

(rat, healthy, 3–5 days old)

IL-1β + 50 µg/ml EVs (24–96 h)

Increased cell proliferation and migration and reduced apoptosis

Increased ACAN; reduced MMP13 [Western blot]

[30]

BMSCs (human/rat)

Nucleus pulposus cells

(human, IVDD, 25–43 y/o)

TNF-α + 100 µg/mL EVs (48 h)

Increased cell proliferation; reduced senescence and apoptosis

Increased COL2, ACAN; reduced MMP13, ADAMTS5 [Western blot]