Are you are expecting chondrocytes to make mineralized matrix? Normally they don't do that.

If I remember correctly, immature chondrocytes can produce collagen type 1, which is a major component of bone matrix while mature chondrocytes produce collagen type 2, a major component of cartilage. Over time the collagen type 1, "bone template" may mineralize to form bone in vivo, however this process takes months during normal bone remodeling and osteoblasts control mineral deposition.

Article A bit of give and take: the relationship between the extrace...

Cartilage ECM ist not Bone matrix. Chondrocytes do not have any ability of mineralization. The cannot produce HAP. Coculture with osteoblasts (from primary MSC or Saos-2 cell line) could be helpful to overcome this problem.

Hello

And see this link 

Good Luck 

https://www.researchgate.net/post/Is_anyone_working_with_chondrocytes_for_making_ECMs?tpr_view=YGLGHS1mWSyQgLkK8F0ctAgbUn8QI713eYr5_2

Hi! Once you work with Chondrocytes you need to keep in mind that they need to proliferate so people use to add Insuline and FGF2! Once the proliferation is finished you should add BMP12, Ascorbic acid, insuline and T3. If you stay like that for more than 3 weeks you should find hypertrophied chondrocytes. They are going to produce an ECM matrix that should be able to be mineralized. For this mineralization as people said before you should try a co-culture or maybe a mineral rich culture media. Good luck!

I think if you are making hydroxyapatite type ECM then you should use MSC's because the chondrocytes are having no role in creation of hydroxyapatite type ECM. they are only present in cartilage while hydroxyapatite is part of bone.

Hello

i agree with all researchers and article in link will help you

Good Luck 

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3445147/

Thank you all for your input so far. My next question is does anyone have a SEN micrograph of chondrocytes or mesenchymal cells. As I would like to compare the images I have. Thank you in expectation