Biosynthesis of Bacterial Cellulose by Extended Cultivation with Multiple Removal of BC Pellicles.

Extended cultivation with multiple removal of BC pellicles is proposed herein as a new biosynthetic process for bacterial cellulose (BC). This method enhances the BC surface area by 5-11 times per unit volume of the growth medium, improving the economic efficiency of biosynthesis. The resultant BC gel-films were thin, transparent, and congruent. The degree of polymerization (DP) and elastic modulus (EM) depended on the number of BC pellicle removals, vessel shape, and volume. The quality of BC from removals II-III to VII was better than from removal I. The process scale-up of 1:40 by volume increased DP by 1.5 times and EM by 5 times. A fact was established that the symbiotic Medusomyces gisevii Sa-12 was adaptable to exhausted growth medium: the medium was able to biosynthesize BC for 60 days, while glucose ran low at 24 days. On extended cultivation, DP and EM were found to decline by 39-64% and 57-65%, respectively. The BC gel-films obtained upon removals I-VI were successfully trialed in experimental tension-free hernioplasty.

Early morphological changes in tissues when replacing abdominal wall defects by bacterial nanocellulose in experimental trials.

Experimental trials were done on five dogs to explore if an anterior abdominal wall defect could be repaired using wet (99.9%), compact BNC membranes produced by the Мedusomyces gisevii Sa-12 symbiotic culture. The abdominal wall defect was simulated by middle-midline laparotomy, and a BNC membrane was then fixed to open aponeurotic edges with blanket suture (Prolene 4-0, Ethicon). A comparative study was also done to reinforce the aponeurotic defect with both the BNC membrane and polypropylene mesh (PPM) (Ultrapro, Ethicon). The materials were harvested at 14 and 60 days postoperative to visually evaluate their location in the abdominal tissues and evaluate the presence of BNC and PPM adhesions to the intestinal loops, followed by histologic examination of the tissue response to these prosthetics. The BNC exhibited good fixation to the anterior abdominal wall to form on the 14th day a capsule of loose fibrin around the BNC. Active reparative processes were observed at the BNC site at 60 days post-surgery to generate new, stable connective-tissue elements (macrophages, giant cells, fibroblasts, fibrin) and neocapillaries. Negligible intraperitoneal adhesions were detected between the BNC and the intestinal loops as compared to the case of PPM. There were no suppurative complications throughout the postsurgical period. We noticed on the 60th day after the BNC placement that collagenous elements and new capillary vessels were actively formed in the abdominal wall tissues, generating a dense postoperative cicatrix whose intraperitoneal adhesions to the intestinal loops were insignificant compared to the PPM graft.

The Clinical Significance of the Activation Energy during Cryoglobulin Complex Formation.

The problem of cryoglobulins role in different diseases is very actual. Our preliminary investigations showed that activation energies of protein transition from the cryocomplex into solution correlate with clinical symptoms of cryoglobulinemia. The average meaning of activation energy show that the main type of interaction between the molecules in cryocomplexes is of Van-der-Vaalse type. The dependence of light scattering intensity on the temperature of the serum of patients with hepatitis C virus infection and cryoglobulinemia have been studied. From these data the activation energies of protein transition from the cryocomplex into solution have been calculated. The activation energies correlate with clinical symptoms of cryoglobulinemia. Low activation energies (2.6 +/- 1.4 kDg/M) accompany the kidney damage. If cryoglobulin level is not low at high activation energies the kidney damage is severe due to cryoimmunocomplex deposition in organ.