Hurdles to overcome for mesenchymal stem cell translation from bench to bedside

Table 1 Mesenchymal stem cell-based products that have received market approval from major regulatory agencies

Product name	Developer company	Cell type	Indication	Regulatory body	Country	Year	Ref.
Ryoncil™ (remestemcel-L)	Mesoblast	Allo-BM-MSC	Pediatric SR-aGvHD	United States FDA	United States	2024	[20]
Cupistem®	Anterogen	Auto-AD-MSCs	Perianal Crohn’s fistula	MFDS	South Korea	2012	[19]
Cartistem®	Medipost	UC-MSC	Knee OA	MFDS	South Korea	2012	[19]
Temcell HS®	JCR Pharmaceuticals	Allo-BM-MSC	SR-aGvHD	PMDA	Japan	2015	[19,20]
Amimestrocel (conditional approval)	Platinum Life Excellence Biotech	UC-MSC	SR-aGvHD with gastrointestinal tract involvement in 14 years of age and older	NMPA	China	2025	[21]
Cellgram AMI	Pharmicell	Auto-BM-MSC	AMI	MFDS	South Korea	2011	[19]
NeuroNata-R	Corestem	Auto-BM-MSC	ALS	MFDS	South Korea	2014	[19]
Stempeucel	Stempeutics Research	Allo-BM-MSC	CLI	DCGI	India	2016	[19]
MesestroCell	Cell Tech Pharmed	Auto-BM-MSC	OA	IFDA	Iran	2018	[19]
Stemirac	Nipro Corp	Auto-BM-MSC	SCI	PMDA	Japan	2018	[19]

Allo-BM-MSC: Allogeneic bone marrow-derived mesenchymal stem cells; SR-aGvHD: Steroid-refractory acute graft vs host disease; FDA: Food and Drug Administration; Auto-AD-MSCs: Autologous adipose derived mesenchymal stem cell; MFDS: Ministry of Food and Drug Safety; UC-MSC: Umbilical cord-derived mesenchymal stem cell; OA: Osteoarthritis; PMDA: Pharmaceuticals and Medical Devices Agency; NMPA: National Medical Products Administration; Auto-BM-MSC: Autologous bone marrow-derived mesenchymal stem cell; AMI: Acute myocardial infarction; ALS: Amyotrophic lateral sclerosis; CLI: Critical limb ischemia; DCGI: Drugs Controller General of India; IFDA: Iran Food and Drug Administration; SCI: Spinal cord injury.

Table 2 Methods to detect genetic stability of in vitro expanded mesenchymal stem cells

Assay	What it detects	Strengths	Limitations	Suggested use/frequency	Ref.
Conventional karyotype (G-banding)	Large chromosomal abnormalities	Low cost; detects numerical and structural chromosomal abnormalities	Low resolution (approximately 5-10 Mb), not sufficient to predict full genetic stability, laborious	At master cell bank and before clinical release	[96-98]
FISH	Low mosaicism, minor structural abnormalities	Rapid, sensitive, easy data interpretation	The chromosomal aberration being searched for must be known beforehand	Not a screening technique, complementary to karyotyping for further proof of genotypic stability	[96-98]
M-FISH	Overall view of all chromosomes in a single assay	High resolution (approximately 1.5 Mb)	Highly expensive, difficult to analyze and interpret data	Not to be used to replace karyotyping	[96,99]
a-CGH	Copy number variations	Higher resolution than karyotype (≤ 50 kb), medium cost, no need for metaphases, requires only the genomic DNA	Cannot detect balanced translocations, inversion and intragenic rearrangement; need of experienced cytogenetic specialist	At defined passage thresholds and for new donor lines or when recurrent abnormalities are found	[96-98]
WGS	Single-nucleotide changes and copy number alterations	Highest resolution; comprehensive	Costly; complex analysis; uncertain clinical significance for many variants	As confirmatory test for master bank or if abnormalities suspected	[100]
Telomere length (qPCR)	Telomere attrition	Simple surrogate for replicative senescence	Not definitive for malignancy risk	Periodic, after a certain number of passages	[101]
DNA methylation profiling	Epigenetic drift; aging signatures	Useful for senescence, potency	Interpretation still evolving	For research and characterization; consider for potency correlation	[102-104]

FISH: Fluorescence in situ hybridization; M-FISH: Multiplex/multicolor fluorescence in situ hybridization; a-CGH: Array comparative genomic hybridization; WGS: Whole-genome sequencing; qPCR: Quantitative polymerase chain reaction.

Table 3 Detailed comparison of the therapeutic potential of mesenchymal stem cells derived from various sources

Source	Preferential lineage-specific differentiation	Typical best-fit indications	Pros	Cons	Ref.
Bone marrow	Strong osteogenic and chondrogenic	Bone defects, osteoarthritis, non-union bones	Extensively studied; good for bone and cartilage repair	Lower yield; donor age effect; invasive harvest procedure	[68,118,127]
Adipose tissue	Cardiomyocytes, skeletal muscle cells, neurons, hepatocytes, and tenocytes	Wound healing, ischemic injury, soft tissue repair	High yield of cells from liposuction; abundant tissue source; proliferative; useful for soft tissue regeneration	Lower osteogenic and chondrogenic differentiation compared to bone marrow	[119,120,127,128]
Umbilical cord/Wharton’s jelly	Osteogenic, chondrogenic, adipogenic, vascular, neuronal	Immune modulation, systemic inflammatory disorders, arthritis, cardio- and cerebrovascular	Neonatal origin, high proliferation, immune-privileged, trophic activity, antifibrotic, good for allogeneic off-the-shelf use	Variable processing methods; donor bank logistics	[127,129]
Synovial fluid	Tissue-biased properties (e.g., chondrogenic, neurogenic)	Cartilage repair	Useful for lineage-specific repair	Lower availability; niche-specific handling	[127,130,131]
Dental pulp	Odontoblasts, osteoblasts, endothelial cells, and nerve cells	Neuronal, vascular and odontogenic disorders	Highly proliferative; can be derived from deciduous teeth as well	Tiny primary tissue that gives lower cell yield	[127,132-134]