When an elderly person suffers a fracture, the chances of recovery decrease mainly due to osteoporosis (rapid loss of bone tissue): the bone takes time to recover and this leads to complications, such as bacterial infections. Researchers at Hubei University have developed a technique to accelerate bone regeneration in case of implants and fight infections using a powerful microscopic ally: the bacteria in yogurt.
“After surgery, many elderly patients often suffer from cardiovascular disease because of the delay in healing and long periods in bed, increasing their mortality. In addition, to prevent bacterial infections, patients are given antibiotics, but even so, the increased incidence of multidrug-resistant bacteria is already becoming a very serious problem, ”said Lei Tan, biomaterials engineer and lead author of the study.
Lactobacillus casei is a probiotic used in the manufacture of yoghurts and cheeses, and has been used not only as an ally in the treatment of osteoporosis but also in the fight against resistant microorganisms (such as Staphylococcus aureus, responsible for pneumonia and meningitis, among other diseases) antibiotics. Its use has always been oral, but Tan’s approach takes the bacillus to the surface of the implant itself.
Biofilm free and infected
According to him, “the biofilm that L. casei develops to adhere to the surface where it multiplies has excellent antibacterial efficacy (99.98% against S. aureus) due to the production of lactic acid and bacteriocin [toxins that they produce to inhibit the growth of other bacteria around you]. In addition, the sugar present in the biofilm stimulates macrophages [which eat cellular debris and encourage the production of new tissue], making the implant integrate with the bone more quickly ”.
After the success of the in vitro tests, the method was tested on guinea pigs, to see if the healing of the bones was greater with the new method.
Six mice with a broken tibia received titanium implants – three, the standard implant and three, coated with L. casei biofilms. After four weeks, the bone tissue of rats with the biofilm implant had grown by 27%, compared to 16% in animals with regular implants (the latter still developed infections).