ABSTRACT
Osteoarthritis is a common degenerative joint disease, and cartilage damage is often considered an early factor in irreversible joint degeneration. Repairing damaged cartilage remains a medical challenge due to its limited ability to self-repair and regenerate. In recent years, the application of tissue engineering strategies to treat cartilage defects has been recognized as an emerging therapeutic avenue. Acellular cartilage matrix (ACM) is an ideal material for cartilage repair and regeneration as it retains the extracellular matrix structure and bioactive components of natural cartilage, mimicking the extracellular environment of natural cartilage to the greatest extent. Type II collagen is the main type of hyaline cartilage and plays an important role in regulating the mechanical properties of cartilage tissue. It has been shown that type II collagen, growth factors and the hypoxic microenvironment play important roles in promoting cartilage regeneration. Type II collagen induces cell aggregation and chondrogenic differentiation in a specific way; Various growth factors contained in the ACM induce Sox9 expression and promote chondrogenic differentiation of stem cells; The hypoxic microenvironment upregulates the expression of type II collagen (COL2A1), Sox9 and maintains chondrocyte phenotype. In addition, ACM has been widely used in cartilage regeneration studies, either as a decellularized scaffold, hydrogel or 3D bioprinting technique for the repair of defective cartilage. Although the ACM-derived biomaterials discussed in this paper have many advantages, there are still some difficulties in their practical applications, such as loss of ACM components and reduced scaffold performance, which are still worth exploring in depth.
ABSTRACT
Objective To investigate the afflication of non-humidified low flow nasal oxygen inhalation in the ICU patients. Methods Four hundred patients hospitalized in ICU and needing continuous low-flow oxygen inhalation for more than 24 h were randomly divided into experiment group and control group equally.The experiment group were managed with dried humidification bottle oxygen inhalation and the control group conventional humidified bottle oxygen inhalation.The two groups were compared in terms of 24 h respiratory reactions,bacterial contamination of the humidified bottle,complaints of patients about oxygen inhalation noises and time for nurses to change the humidified bottles.Results The two groups had no significant difference in adverse symptoms(all P>0.05).The rate of bacterial contamination in the experimental group was significantly lower than the control group(P<0.05),the noises were lower and the time for changing the bottle shorter(P<0.05).Conclusion Non-humidified low flow nasal oxygen inhalation in ICU patients is good for reducing the rate of bacterial contamination of humidified bottle and lowering workload and oxygen-inhaling noises.