Organotypic in vitro block culture model to investigate tissue-implant interface. An experimental study on pig mandible

In vitro studies of implant-tissue attachment are primarily based on two-dimensional cell culture models, which fail to replicate the three-dimensional native human oral mucosal tissue completely. Thus, the present study aimed to describe a novel tissue culture model using pig mandibular block including alveolar bone and gingival soft tissues to evaluate the tissue attachment to titanium implant provided with hydrothermally induced TiO2 coating. Tissue attachment on TiO2 coated and non-coated implants were compared. Ti-6Al-4V alloy posts were used to function as implants that were inserted in five pig mandibles. Implants were delivered with two different surface treatments, non-coated (NC) titanium and hydrothermal induced TiO2 coated surfaces (HT). The tissue-implant specimens were cultured at an air/liquid interface for 7 and 14 days. The tissue-implant interface was analyzed by histological and immunohistochemical stainings. The microscopic evaluation suggests that pig tissue explants established soft and hard tissue attachment to both implant surfaces. The epithelial cells appeared to attach to the coated implant. The epithelium adjacent to the implant abutment starts to change its phenotype during the early days of the healing process. New bone formation was seen within small pieces of bone in close contact with the coated implant. In conclusion, this in vitro model maintains the viability of pig tissue and allows histologically and immunohistochemically evaluate the tissue-implant interface. HT-induced TiO2 coating seems to have a favorable tissue response. Moreover, this organotypic tissue culture model is applicable for further studies with quantitative parameters to evaluate adhesion molecules present at the implant-tissue interface.

Experimental Study On Antibacterial Properties of Iodine-Coated Implant in Acute Osteomyelitis Model

Purpose We have developed a iodine-coated implant and evaluated its antibacterial properties against Gram-negative bacteria by constructing an experimental osteomyelitis model.Methods In this study, 16 titanium Kirschner-wires were selected, of which 8 titanium K-wires were treated with iodine on the surface by electrophoretic deposition with PVP-I solution. In our study, the standard strain of Escherichia coli (ATCC 25922) was selected, and 16 New Zealand rabbits were selected. There were 8 rabbits in the iodine-coated group and 8 rabbits in the non-iodine-coated group. All animals were drilled in the left proximal tibia after successful anesthesia.After that,the iodine-coated group was implanted with iodine-coated titanium K-wires.Then, 25ul of 2×108CFU/ml bacterial suspension was injected into the bone marrow cavity with pipette gun, and the bone hole was sealed with bone wax.They were reared in cages for 1 week after operation, and evaluated and analyzed by microbiology, histopathology, scanning electron microscopy, etc.Results The results of gross wound score and microbiology showed that the wound infection of the iodine-coated group was less severe than that of the non-iodine-coated group, which was confirmed by the histopathological results. Scanning electron microscopy and confocal microscopy showed that the amount of bacteria on the surface of iodine-coated K-wires was significantly lower than that non-iodine-coated K-wires. Conclusions In this study, we have verified that the iodine-coated titanium implant could effectively inhibit E. coli infection in the early stage of infection by constructing an acute osteomyelitis model.

116 Effect of Coated and Non-coated Steroidal Implants on Growth Performance, Dietary Net Energy Utilization and Carcass Traits of Feedlot Finishing Steers

Maine-Anjou x Angus steers (n = 156, initial BW 366 ± 37.2 kg) were used in a 132-d finishing experiment at the Ruminant Nutrition Center in Brookings, SD. Steers were weighed on two consecutive days and assigned into 5 weight blocks. Within each weight block steers were randomly assigned to two implant types (equal steroidal hormone dose; both from Zoetis, Parsippany, NJ) and two dietary treatments in a 2 × 2 factorial arrangement. Implant treatments consisted of 1) Coated implant, 200 mg trenbolone acetate (TBA), 28 mg estradiol benzoate (EB) (Synovex ONE Feedlot, ONE) or 2) Non-coated implant, 200 mg TBA, 28 mg EB (Synovex PLUS; PLUS), placed in the left ear. Dietary treatments were 1) 15% or 2) 30% corn silage (DM basis). No interaction between implant and corn silage inclusion was observed for carcass-adjusted (hot carcass weight / 0.63) growth performance, dietary net energy (NE) utilization or carcass traits (P ≥ 0.16). Bunks were managed using a slick bunk approach and all diets contained (DM basis) 33 mg/kg monensin sodium. Implant status was checked on d 28 by a single trained evaluator; steers with missing implants were immediately re-implanted. There was no difference in carcass-adjusted growth performance between implants (P ≥ 0.85). There were no differences in observed NE or the observed-to-expected ratio of NE for either growth or maintenance (P ≥ 0.90). No differences were observed for dressing percent, hot carcass weight, ribeye area, or rib fat (P ≥ 0.22). Marbling differed between implant treatments (433 to 466 ± 8.7; P = 0.01) for PLUS and ONE respectively. Implanting cattle with a coated implant had no detrimental effect on growth performance or carcass traits, but it did increase marbling scores.

275 Comparison of Revalor-xh with a revalor-ih/revalor-h/revalor-200 Re-implant Program on Feedlot Cattle

A commercial feedlot trial evaluated a 3-implant re-implant program using Revalor-IH/Revalor-H/Revalor-200 compared to a single Revalor-XH (200 mg TBA and 20 mg E2 partially coated) implant strategy on feedlot performance and carcass characteristics of calf fed heifers. Heifer calves (n = 1356) were purchased through time and blocked by source and arrival date, assigned randomly to pen within block, and pen assigned randomly to one of the two implant treatments. Heifers who received the 3-implant re-implant treatment were re-implanted on d67 with Revalor-H and on d137 with Revalor-200. Each block of cattle were harvested on the same study day, which averaged 215 days on feed. Performance data were analyzed as a randomized block design, with the blocking factor as source/arrival time being considered random. Implant strategy was analyzed as a fixed effect with pen (n = 20) as the experimental unit. On a live basis, heifers implanted with Revalor-XH had a tendency for a greater gain efficiency (P = 0.06) though there were no significant differences between implant treatments for final body weight, gain or intake (P ≥ 0.15). There were no significant differences between implant treatments for hot carcass weight, gain, or gain efficiency (P ≥ 0.29) on a carcass-adjust basis. Marbling score and 12th rib fat thickness were not impacted by implant treatment (P ≥ 0.80); however, there was an increase in LM area (P = 0.02) for heifers on the 3-implant re-implant treatment compared to the Revalor-XH implanted heifers. There was also a tendency for a greater calculated YG in heifers who received Revalor-XH (P = 0.07). Heifers fed for approximately 215 d with a single Revalor-XH implant performed similarly to heifers fed the same amount of days receiving a 3-implant re-implant strategy using Revalor-IH/H/200 combination.

Effects of Corn Silage Inclusion Level and Type of Anabolic Implant on Animal Growth Performance, Apparent Total Tract Digestibility, Beef Production per Hectare, and Carcass Characteristics of Finishing Steers

Maine-Anjou × Angus cross-bred steers (n = 156 steers; initial body weight (BW) 366 ± 37.2 kg) were used in a 132 d finishing study conducted at the Ruminant Nutrition Center (RNC) in Brookings, SD. Steers were blocked by weight (n = 5 BW blocks) and randomly assigned to an implant and dietary treatment of a randomized complete block design with each pen containing seven to eight steers (n = 20 pens). Dietary treatments consisted of (1) 15% (CS15) or (2) 30% corn silage (CS30) where corn silage displaced corn grain in the diet. Steers received one of two implants (both from Zoetis, Parsippany, NJ) containing equal doses of trenbolone acetate (TBA) and estradiol benzoate (EB): (1) Synovex PLUS (non-coated implant; 200 mg TBA and 28 mg EB; PLUS) or (2) Synovex ONE Feedlot (coated implant; 200 mg TBA and 28 mg EB; ONE-F). Bunks were managed using a slick bunk approach, and all diets contained dry matter (DM) basis 33 mg/kg monensin sodium. All steers were offered ad libitum access to feed, and feeding occurred twice daily in equal portions. There was no interaction between the implant and dietary treatment for any variables measured (p ≥ 0.08). Carcass-adjusted basis final BW, average daily gain (ADG), and grain to feed (G:F) were increased (p ≤ 0.02) by 2.2%, 6.5%, and 7.2%, respectively, for CS15. Observed net energy (NE) and the ratio of observed-to-expected NE for maintenance and gain was not influenced (p ≥ 0.15) by silage inclusion treatment. Beef production per hectare was not impacted (p ≥ 0.13) by corn silage inclusion level. Fecal output was increased, and digestibility coefficients for dry matter, organic matter, and crude protein were decreased in CS30 (p ≤ 0.03). Dressing percent and hot carcass weight (HCW) were greater (p ≤ 0.02) in CS15. Implant type did not influence any traits measured (p ≥ 0.14) except for marbling. Marbling was decreased for PLUS (433 vs. 466 ± 17.5; p = 0.02) compared to ONE-F steers. Similar beef produced per hectare of crop land-based upon silage feeding level means producers can feed greater inclusions of corn silage to finishing cattle without impacting carcass quality or beef production; implanting with a coated implant had no detrimental effects to growth performance but increases marbling scores.

Comparative Analysis of Morphological and Release Profiles in Ocular Implants of Acetazolamide Prepared by Electrospinning

The visual impairment that often leads to blindness causes a higher morbidity rate. The goal of this work is to create a novel biodegradable polymeric implant obtained from coaxial fibers containing the dispersed drug—acetazolamide—in order to achieve sustained drug release and increase patient compliance, which is of the highest importance. Firstly, during this work, uncoated implants were produced by electrospinning, and rolled in the shape of small cylinders that were composed of uniaxial and coaxial fibers with immobilized drug inside. The fibers were composed by PCL (poly ε-caprolactone) and Lutrol F127 (poly (oxyethylene-b-oxypropylene-b-oxyethylene)). The prepared implants exhibited a fast rate of drug release, which led to the preparation of new implants incorporating the same formulation but with an additional coating film prepared by solvent casting and comprising PCL and Lutrol F127 or PCL and Luwax EVA 3 ((poly (ethylene-co-vinyl acetate)). Implants were characterized and in vitro release profiles of acetazolamide were obtained in phosphate buffered saline (PBS) at 37 °C. The release profile of the acetazolamide from coated implant containing Luwax EVA 3 is considerably slower than what was observed in case of coated implants containing Lutrol F127, allowing a sustained release and an innovation relatively to other ocular drug delivery systems.