To investigate the effects of different doses of insulin-like growth factor 1 (IGF-1) on the cartilage layer and subchondral bone (SB) during repair of full-thickness articular cartilage (AC) defects.

Design

IGF-1-loaded collagen membrane was implanted into full-thickness AC defects in rabbits. The effects of two different doses of IGF-1 on cartilage layer and SB adjacent to the defect, the cartilage structure, formation and integration, and the new SB formation were evaluated at the 1st, 4th and 8th week postoperation. Meanwhile, after 1 week treatment, the relative mRNA expressions in tissues adjacent to the defect, including cartilage and SB were determined by quantitative real-time RT-PCR (qRT-PCR), respectively.

Results

Different doses of IGF-1 induced different gene expression profiles in tissues adjacent to the defect and resulted in different repair outcomes. Particularly, at high dose IGF-1 aided cell survival, regulated the gene expressions in cartilage layer adjacent defect and altered ECM composition more effectively, improved the formation and integrity of neo-cartilage. While, at low dose IGF-1 regulated the gene expressions in SB more efficaciously and subsequently promoted the SB remodeling and reconstruction.

As with conventional IGF-1 or IGF-1 LR3, IGF-1 DES (1-3) again states that nothing precise can be said about the side effects and that the enumerated things are derived from empirical values. However, what is very well known is that IGF generally causes general growth of tissue, which also affects tumors, etc. Other side effects that may occur are:

– Temporary water retention subcutaneously

– Headache

– Joint pain

– Hunger attacks

– Aching

The preferred method of calculation is reconstituting the 1 mg DES(1-3) IGF -1 vial with 2 ml sterile water or bacteriostatic water. A little tip here is to clean the top of the vial with an alcohol swab to remove any contamination from bacteria before reconstitution.

You have to inject the 2 ml water in the vial at a very slow pace and leaving it for the powder to absorb the water on its own. You have to be cautious and not to shake the vial for absorption and if still any powder remains unmixed, gradually turn the vial anti-clockwise, so that the remaining powder can get mixed evenly.

The reconstituted solution of 1 mg DES(1-3) IGF-1 should always be refrigerated at around 8 degrees Celsius before and after its use. The solution should not be exposed to direct sunlight or heat as it can change the properties of the solution.