Calcification and Biofilms

Aldehyde effects on calcification

Act as nucleation sites for calcium

Equation for Calcification

Mechanical damage + chemical cross-linking = cells and cell fragments in bioprosthetic tissue

Causes of uncontrolled intracellular Ca concentration

Abnormal transport of calcium ions due to reduction of the functional transmembrane pumps and increase permeability of calcium ions

Phosphates

Source is cell membranes and act as nucleation sites to form calcium phosphate Ca3O8P2 crystals

Alkaline phosphatase

ALP: linked to the cell membrane, promotes calcification, specifically of HA crystals

Effects of Flow Dynamics

Turbulent flow increases pathologic calcification

Connection to Fibrous Encapsulation

Has the potential to calcify, especially in breast implants and intraocular devices

Use of trivalent metal ions

Fe3+ and Al3+ compete with calcium to create different salts

Potential biofilm substrates

Contact lenses, venous or urinary catheters, breast implants, pacemakers, dental implants, joint prostheses

Potential sources of biofilms

Wound infection, chronic otitis (ear infection), dental plaque, lung infection in patient with cystic fibrosis

Osteomyelitis

inflammation of bone and bone marrow causing severe inflammation, swelling, septic implant loosening, etc

Antibiotic and multidrug resistance

Bacteria evolve to be drug-resistant to more and more drugs which makes many treatments nonfunctional

Superficial immediate infections

In the site of the wound, produced by skin bacteria

Deep immediate Infections

In the site of an implant, produced by skin or airborne bacteria carried in during the implant process

Late infections

Months to years after implantation & spread through contamination by blood and other body fluids

bacterial endocarditis

inflammation of inner lining of heart (the endocardium)

Extracellular polymeric substances (EPS)

polysaccharides, DNA, and proteins that form self-produced matrix around bacteria in a biofilm

Purposes of the Biofilm matrix

isolate the bacteria from immune defenses, physical stresses & antibiotic therapy

Bacterial Attachment Phase I

Reversible association: passive and non-specific

Bacterial Attachment Phase II

Irreversible molecular bridging modulated by specific adhesins