Effect of Various Toothpaste Tablets on Gloss and Surface Roughness of Resin-based Composite Materials

OBJECTIVES

To evaluate the effect of various toothpaste tablets on gloss and surface roughness of resin-based composite.

METHODS AND MATERIALS

Sixty-four resin-based composite specimens were divided into four groups of 16 specimens each. Gloss and roughness were measured before and after simulated brushing with three types of toothpaste tablets and one conventional toothpaste: CT: Chewtab Toothpaste Tablets; AT: Anticavity Toothpaste Tablets; HC: Charcoal Toothpaste Tablets; CP: Cavity Protection toothpaste. The Kruskal- Wallis procedure was performed to compare the differences by groups. Post-hoc comparisons were conducted with Bonferroni corrections (α=0.05).

RESULTS

There was a significant drop in gloss for all groups. CT and AT maintained the highest gloss with means of 81.6 GU and 74.1 GU, respectively. The lowest gloss of 24.5 GU was observed for HC. There was a significant increase in roughness for all groups except for CT. CT had the lowest roughness with a mean of 0.034 μm, while HC had the highest roughness with a mean of 0.074 μm. There was a significant correlation between post-brushing gloss and post-brushing roughness (p<0.001, r=-0.884).

CONCLUSION

Chewtab Toothpaste Tablets had the least effect on gloss and roughness, while Charcoal Toothpaste Tablets had the most negative effect on the surface properties of resin-based composites.

Feasibility of a Group-based Telehealth Psychosocial Intervention for Women with Non-Small Cell Lung Cancer (NSCLC)

Purpose of study: As women with lung cancer are particularly vulnerable to psychological distress and social isolation, which may be further exacerbated by current COVID-19 physical distancing precautions, we examined the feasibility and acceptability of a group-based telehealth psychosocial intervention for this understudied patient population. Methods: Women with a recent diagnosis (3 months) of non based telehealth psychosocial intervention for this understudied patient population. Methods: Women with a recent diagnosis (3 months) of non-small cell lung cancer (NSCLC) currently undergoing treatment completed baseline measures of computer literacy and were randomized to a group-based telehealth psychosocial intervention consisting of ether coping skills or attention control (AC) psychoeducation. Both arms consisted of five, 60 min. telehealth (video conference over Zoom) sessions. Groups were comprised of 3–5 members and led by a masters-level clinician. Participants completed one “practice run” with technology prior to starting the group session. After the final session, patients rated overall experience of intervention delivery and telehealth platform. Results: Seventy patients (mean age = 66 yrs, 54% &gt;65 yrs; 71% non-Hispanic White; 50% college educated; 75% advanced stage) consented (63% consent rate) and 65 were randomized to intervention or AC. At baseline, 47% of patients indicated daily computer use while 50% said they rarely or never use a computer. Attendance was high in both arms with 63% of patients attending all sessions (means: intervention = 3.18; AC = 3.56). Across arms, 89% preferred group delivery and 92% preferred online delivery. The majority used a smartphone or tablet to participate (72%). Regarding the Zoom platform, 71% said it was easy to use, 65% would recommend it to others, and 41% felt comfortable with it after one use. Only 44% thought that telehealth was the same as it would have been in-person. Conclusions: The present findings suggest the feasibility and acceptability of delivering a group-based psychosocial intervention via telehealth for middle to older aged women with NSCLC undergoing treatment, which may be particularly beneficial to address isolation during the current season of physical distancing.

Behaviour change interventions to influence antimicrobial prescribing: a cross-sectional analysis of reports from UK state-of-the-art scientific conferences

BACKGROUND

To improve the quality of antimicrobial stewardship (AMS) interventions the application of behavioural sciences supported by multidisciplinary collaboration has been recommended. We analysed major UK scientific research conferences to investigate AMS behaviour change intervention reporting.

METHODS

Leading UK 2015 scientific conference abstracts for 30 clinical specialties were identified and interrogated. All AMS and/or antimicrobial resistance(AMR) abstracts were identified using validated search criteria. Abstracts were independently reviewed by four researchers with reported behavioural interventions classified using a behaviour change taxonomy.

RESULTS

Conferences ran for 110 days with >57,000 delegates. 311/12,313(2.5%) AMS-AMR abstracts (oral and poster) were identified. 118/311(40%) were presented at the UK's infectious diseases/microbiology conference. 56/311(18%) AMS-AMR abstracts described behaviour change interventions. These were identified across 12/30(40%) conferences. The commonest abstract reporting behaviour change interventions were quality improvement projects [44/56 (79%)]. In total 71 unique behaviour change functions were identified. Policy categories; "guidelines" (16/71) and "service provision" (11/71) were the most frequently reported. Intervention functions; "education" (6/71), "persuasion" (7/71), and "enablement" (9/71) were also common. Only infection and primary care conferences reported studies that contained multiple behaviour change interventions. The remaining 10 specialties tended to report a narrow range of interventions focusing on "guidelines" and "enablement".

CONCLUSION

Despite the benefits of behaviour change interventions on antimicrobial prescribing, very few AMS-AMR studies reported implementing them in 2015. AMS interventions must focus on promoting behaviour change towards antimicrobial prescribing. Greater focus must be placed on non-infection specialties to engage with the issue of behaviour change towards antimicrobial use.

Expression profiling stratifies mesothelioma tumors and signifies deregulation of spindle checkpoint pathway and microtubule network with therapeutic implications

BACKGROUND

Malignant pleural mesothelioma (MPM) is a lethal neoplasm exhibiting resistance to most treatment regimens and requires effective therapeutic options. Though an effective strategy in many cancer, targeted therapy is relatively unexplored in MPM because the therapeutically important oncogenic pathways and networks in MPM are largely unknown.

MATERIALS AND METHODS

We carried out gene expression microarray profiling of 53 surgically resected MPMs tumors along with paired normal tissue. We also carried out whole transcriptomic sequence (RNA-seq) analysis on eight tumor specimens. Taqman-based quantitative Reverse-transcription polymerase chain reaction (qRT-PCR), western analysis and immunohistochemistry (IHC) analysis of mitotic arrest deficient-like 1 (MAD2L1) was carried out on tissue specimens. Cell viability assays of MPM cell lines were carried out to assess sensitivity to specific small molecule inhibitors.

RESULTS

Bioinformatics analysis of the microarray data followed by pathway analysis revealed that the mitotic spindle assembly checkpoint (MSAC) pathway was most significantly altered in MPM tumors with upregulation of 18 component genes, including MAD2L1 gene. We validated the microarray data for MAD2L1 expression using quantitative qRT-PCR and western blot analysis on tissue lysates. Additionally, we analyzed expression of the MAD2L1 protein by IHC using an independent tissue microarray set of 80 MPM tissue samples. Robust clustering of gene expression data revealed three novel subgroups of tumors, with unique expression profiles, and showed differential expression of MSAC pathway genes. Network analysis of the microarray data showed the cytoskeleton/spindle microtubules network was the second-most significantly affected network. We also demonstrate that a nontaxane small molecule inhibitor, epothilone B, targeting the microtubules have great efficacy in decreasing viability of 14 MPM cell lines.

CONCLUSIONS

Overall, our findings show that MPM tumors have significant deregulation of the MSAC pathway and the microtubule network, it can be classified into three novel molecular subgroups of potential therapeutic importance and epothilone B is a promising therapeutic agent for MPM.

The major genetic determinants of HIV-1 control affect HLA class I peptide presentation

Infectious and inflammatory diseases have repeatedly shown strong genetic associations within the major histocompatibility complex (MHC); however, the basis for these associations remains elusive. To define host genetic effects on the outcome of a chronic viral infection, we performed genome-wide association analysis in a multiethnic cohort of HIV-1 controllers and progressors, and we analyzed the effects of individual amino acids within the classical human leukocyte antigen (HLA) proteins. We identified >300 genome-wide significant single-nucleotide polymorphisms (SNPs) within the MHC and none elsewhere. Specific amino acids in the HLA-B peptide binding groove, as well as an independent HLA-C effect, explain the SNP associations and reconcile both protective and risk HLA alleles. These results implicate the nature of the HLA-viral peptide interaction as the major factor modulating durable control of HIV infection.

Phase II randomized study of biomarker-directed treatment for non-small cell lung cancer (NSCLC): The BATTLE (Biomarker-Integrated Approaches of Targeted Therapy for Lung Cancer Elimination) clinical trial program

8024

Background: Treatment for patients (pts) with recurrent NSCLC has limited efficacy despite the use of new targeted agents. Identifying biomarkers to predict tumor response will help personalize therapy for individuals. Methods: Eligible pts had prior chemotherapy, ECOG PS 0–2, and when enrolled, required 2 fresh core needle biopsy specimens to test 11 biomarkers related to 4 molecular pathways in NSCLC: EGFR, Kras, and Braf gene mutation (PCR-based sequencing), EGFR and Cyclin D1 copy number analyses (FISH), and 6 proteins via IHC (VEGF/R and RXR receptors/Cyclin D1). Based on eligibility and tumor biomarker analyses, pts were randomized into 1 of 4 treatments: erlotinib (E) 150 mg qd; sorafenib 400 mg bid, vandetanib 300 mg qd; E 150 mg + bexarotene 400 mg/m2 qd. The primary endpoint is 8-week progression-free status. The first 97 pts were equally randomized, with subsequent pts adaptively randomized under a Bayesian framework. Results: Since 11/2006, 227 pts have been enrolled and 171 randomized and treated (median age 62 yrs, 89 males, 137 Caucasians, 11 Asians, 107 former and 38 never smokers). Accrual has proceeded well (average 9 pts per month). 112 of the biopsied lesions were lung, with a pneumothorax rate of 12.1% (15 of 124 pts; grade 1–2 only; lung, mediastinal and pleural sites). 168 pts (74%) have complete biomarker profiles and 7 (3%) have partial. Histology: adenocarcinoma (75%), squamous (11%), large cell (13%). Mutation frequency was 19% EGFR, 15.4% Kras, and 2.9% Braf. 2 tumors contained both EGFR and Kras mutations, and 2 cases had both Kras and Braf mutations. EGFR polysomy by FISH was 36.4%, and gene amplification 21%. Cyclin D1 amplification was 16.3%. Treatment-related adverse events (grade 3 or more) were 6.5%. Conclusions: We have demonstrated that biopsies are safe and feasible for biomarker-directed studies. The study continues enrollment to 200 evaluable pts at which point the results will be unblinded. BATTLE is one of the first studies in advanced lung cancer to prospectively utilize biomarker analysis of fresh biopsies to direct pt treatment, and is a step towards personalizing therapy in NSCLC. Supported by grant DoD W81XWH-6–1-0303.

No significant financial relationships to disclose.

SWOG S0509: A phase II study of novel oral antiangiogenic agent AZD2171 (NSC-732208) in malignant pleural mesothelioma

7511

Background: Preclinical studies suggest the autocrine growth loop involving VEGF and its receptors is a relevant therapeutic target for malignant pleural mesothelioma (MPM). We evaluated AZD2171, a potent tyrosine kinase inhibitor (TKI) of VEGFR1/2 in MPM. Methods: MPM patients (pts) after platinum-based chemotherapy, with PS 0–2, measurable disease and adequate organ function were treated with oral daily dosing of AZD2171 45 mg. Study endpoints were response rate, progression free survival (PFS), overall survival (OS), frequency/severity of toxicities, and correlation of clinical outcomes with tumor and serum biomarkers. Results: 54 pts were registered between November 2005 and April 2008; 45 pts are eligible for response and 46 for toxicity analysis. Median age was 66.8 yrs; M/F: 37/9. Tumor response by RECIST was seen in 4/45 (9%) of pts; of these responders, 2 pts with bulky disease had 56% and 91% tumor shrinkage, respectively. 15/45 (33%) had SD; 21/45 (47%) had PD; 1/45 (2%) had early death. Thirty-five pts have died. For 46 pts, median PFS is estimated at 3 months; median OS is estimated at 10 months. For 46 pts, frequent grade 1–3 toxicities included anorexia (30%), diarrhea (63%), fatigue (60%), hypertension (67%), and proteinuria (28%). There were 8 grade 4 events: Cognitive disturbance, colitis, confusion, ileal perforation, hypertension, hyponatremia, hypotension, and renal failure. Conclusions: AZD2171 has antitumor activity in MPM, with a DCR (CR/PR/SD) of 42% by RECIST, which has limitations in measuring response in pleural tumors. Notably, 2 pt tumors were exquisitely sensitive to this drug. Toxicities were consistent with those of the anti-angiogenic TKI class of drugs. Studies correlating outcome measures with tumor hypoxia- and angiogenesis-related gene expression and circulating endothelial cells are underway. Based on these data, we are proceeding in SWOG with a study of pemetrexed/cisplatin ± AZD2171 (S0905). This investigation was supported in part by the following PHS Cooperative Agreement grant numbers awarded by the National Cancer Institute, DHHS: CA32102, CA38926, CA14028, CA46441, CA105409, CA13612, CA45808, CA20319, CA86780, CA35090, CA67663, CA46282, CA42777, CA76448, CA04919, CA35176, CA63848, CA27057, CA16385.

[Table: see text]

Integrating microRNA and mRNA expression profiling using a novel algorithm identified a small set of unique genes upregulated in malignant pleural mesothelioma (MPM)

e22111

Background: We employed a global profiling strategy using miRNA microarrays in MPM cell lines and archival tumor tissue. Methods: We isolated total RNA from 4 MPM cell lines, 2 control cell lines, and 16 tissue specimens from patients with resected MPM (n=8) and normal counterpart (n=8) patients as controls. Total RNA was labeled with Cyanine 3, then hybridized with Agilent human miRNA microarray v1 slides. Results: Preliminary miRNA profiles show up-regulation of 44 versus down-regulation of 29 miRNA's in MSTO-211H cancer cells compared to HCT-4012 (pleural telomerase-transformed control). Profiling of 16 tissue specimens (8 normal vs 8 MPM) revealed down-regulation of 11 miRNA's in MPM tumor tissue. To focus on relevant miRNA that regulate genes involved in carcinogenesis and progression, we identified > 1000 unique genes using the online targetscan 4.2 program ( http://www.targetscan.org ), which predicts biological targets of miRNAs by identifying the presence of conserved 8-mer and 7-mer sites that match the seed region of each miRNA. We then explored a novel screening strategy, which combines mRNA expression dataset with the miRNA dataset, to narrow the list of relevant miRNA's. We conducted gene expression profiling on the cell lines and MPM tissue samples with Affymetrix U133 plus 2.0 chips. Bioinformatic analysis was conducted with MeV: MultiExperiment Viewer software, data reduction techniques (Correspondance Analysis), hierarchical clustering methods, and Serial Analysis for Microarray (SAM), and showed up-regulation of ∼300 genes in MPM compared to normal tissues. We then computed of the ∼300 mRNA's up-regulated in MPM only 32 are recognized by the 11 down-regulated miRNA's using the targetscan 4.2 algorithm. Most of the miRNA's regulate single messages while ∼20 % of the messages are regulated by more than 1 miRNA's. Some of these targets include Ets variant 1 and Protein kinase C - epsilon. Conclusions: This innovative approach of selecting highly relevant miRNA is feasible and enables discovery of novel genes based on their ability to be bound by single or multiple miRNA's. Validation of our profiling studies using real-time PCR and protein analysis methods will be presented.

No significant financial relationships to disclose.

Rapamycin enriches for CD4(+) CD25(+) CD27(+) Foxp3(+) regulatory T cells in ex vivo-expanded CD25-enriched products from healthy donors and patients with multiple sclerosis

BACKGROUND

CD4(+) CD25(bright+) regulatory T cells (Treg) can be expanded to clinical doses using CD3/CD28 Ab-coated beads plus IL-2. However, this method requires high purity of the starting population to prevent overgrowth by non-regulatory T cells. Rapamycin, an agent that inhibits T-cell proliferation but selectively spares Treg, may be a means to expand Treg from less pure CD25-enriched cells.

METHODS

CD25-enriched cells were prepared by a single-step immunomagnetic-selection using anti-CD25 microbeads. The cells were activated with a single addition of anti-CD3/CD28 beads and expanded in ex vivo 15-5% HS and autologous CD4(+) CD25(-) feeder cells,+/-rapamycin (0.01-20 ng/mL). IL-2 was added on day 3. Cells were rested for 2 days in ex vivo 15-5% HS and tested for phenotype, intracellular Foxp3 protein and suppressor activity.

RESULTS

In the absence of rapamycin, CD25-enriched fractions expanded >17 000-fold by 21 days. Although suppressor activity was detected to day 14, it declined significantly by 21 days as non-regulatory cells expanded. The addition of rapamycin inhibited expansion of non-regulatory T cells at doses > or =1 ng/mL while increasing suppressor activity and the percentage of CD4(+) CD25(+) CD27(+) Foxp3(+) cells. Rapamycin did not enrich for Foxp3(+) cells in expanded cultures of CD4(+) CD25(-) cells. Treg were also readily expanded in cultures of CD25-enriched cells obtained from patients with multiple sclerosis in the presence of rapamycin.

DISCUSSION

The addition of 1-20 ng/mL rapamycin to CD25-enriched cultures increased the purity of cells with the phenotype and function of Treg. This approach may alleviate the need for rigorous enrichment of Treg prior to activation and expansion for potential clinical use.

Final results of a phase II study of erlotinib, docetaxel and cisplatin in patients with recurrent/metastatic head and neck cancer

6013

Background: Interrupting the epidermal growth factor receptor (EGFR) signaling pathway has shown promise in a variety of cancers and preclinical data has demonstrated possible synergy with platinums and taxanes. Treatment options for recurrent/metastatic HNSCC are limited. A study of cisplatin and docetaxel showed a response rate of 40% and 9.6 month median survival. Erlotinib, an EGFR tyrosine kinase inhibitor, had a 4.3% response rate as single agent in HNSCC. Because of the possible synergy and efficacy, we proposed to study the combination of cisplatin, docetaxel and erlotinib in advanced HNSCC. Methods: Patients (pts) were required to have adequate performance status, measurable disease, no prior EGFR therapy, and may have received prior induction, concomitant or adjuvant chemotherapy, but not for recurrent/metastatic disease. Sites of disease included squamous cell head and neck sites excluding nasopharynx and sinus. Treatment included docetaxel 75 mg/m2 and cisplatin 75 mg/m2 intravenously every 3 weeks and erlotinib 150 mg by mouth daily. All agents were started on day 1. Pts were treated with growth factor support. Results: The trial has completed accrual to 50 pts. 47 pts are available for analysis at this time. Median age is 56 years (range 39–72). ECOG PS is 0, 1, 2 (6, 29, 2 pts). 43 pts are evaluable for efficacy. All responses were confirmed via RECIST. Complete responses have been in observed in 4 pts, partial responses in 25 pts and 12 pts have stable disease for an overall response rate of 67% and disease control rate of 95%. After a follow-up of 19 months, median overall survival was 11 months (8.61, 22.5, 95% CI) and progression free survival was 6.01 months (4.37, 8.25). 6 pts had grade 3/4 febrile neutropenia, 4 pts had grade 3/4 dehydration, 3 pts had grade 3 diarrhea, and 2 pts had grade 3/4 GI bleeding. The most common grade 1–2 toxicities were diarrhea, nausea, and rash. Conclusions: The combination of cisplatin, docetaxel and erlotinib is well tolerated and has very encouraging activity in recurrent/metastatic HNSCC. Tissues are being collected and analyzed for correlative markers including downstream EGFR pathway markers (p-akt, mek, k-ras). Final efficacy and biomarker results will be presented at the annual meeting.

No significant financial relationships to disclose.

Eighth international mesothelioma interest group

The eighth International Mesothelioma Interest Group (IMIG) meeting was held in Chicago, IL, United States, in 19-22 October 2006 to discuss mesothelioma - the cancer often linked to asbestos exposure. It is a very aggressive malignancy with a median survival of less than 1 year from diagnosis. Millions of people have been exposed worldwide to asbestos, especially during the second half of the twentieth century when asbestos use increased significantly. The tons of asbestos utilized in the past remain a health hazard for current and future generations because asbestos is difficult to be disposed off. This makes asbestos and mesothelioma research a public health issue in addition to a medical problem. Moreover, the very high costs of asbestos litigation have a significant impact on the whole economy. In the United States, up until 2001, defendant companies had paid 54 billion dollars in claims and estimated future liabilities ranged from 145 to 210 billion. Therefore, asbestos research is of great interest to a large audience that includes patients, millions of asbestos-exposed individuals, scientists, physicians, public health officials, politicians, unions of asbestos workers, lawyers and the public at large. During the past few years, there has been significant progress in understanding the process of mineral fiber carcinogenesis and mesothelioma pathogenesis. With improved understanding of the pathogenesis of mesothelioma, new diagnostic, preventive and therapeutic options are being developed. A total of 247 papers were presented at the IMIG: the abstracts of these presentations were published in Lung Cancer, Supplement 1, October 2006. Here, experts in different disciplines critically review some of the most exciting presentations of the IMIG meeting. The result is a comprehensive review of the research field of asbestos carcinogenesis and mesothelioma, and of the progress that has been made in recent years in both basic and clinical sciences.

Characterization of multicomponent monosaccharide solutions using an enzyme-based sensor array

We report the development of a sensor for rapidly and simultaneously measuring multiple sugars in aqueous samples. In this strategy, enzyme-based assays are localized within an array of individually addressable sites on a micromachined silicon chip. Microspheres derivatized with monosaccharide-specific dehydrogenases are distributed to pyramidal cavities anisotropically etched in a wafer of silicon (100) and are exposed to sample solution that is forced through the cavities by a liquid chromatography pumping system. Production of fluorescent reporter molecules is monitored under stopped-flow conditions when localized dehydrogenase enzyme systems are exposed to their target sugars. We demonstrate the capability of this analysis strategy to quantify beta-D-glucose and beta-D-galactose at low micromolar to millimolar levels, with no detectable cross-talk between assay sites. Analysis is achieved either through fluorescence detection of an initial dehydrogenase product (NADH, NADPH) or by production of a secondary fluorescent product created by hydride transfer from the reduced nicotinamide cofactor to a fluorogenic reagent. The array format of this sensor provides capabilities for redundant analysis of sugars and for monitoring levels of other solution components known to affect the activity of enzymes. The use of this strategy to normalize raw fluorescence signals is demonstrated by the determination of glucose and pH on a single chip. Alternatively, uncertainties in the activity of an immobilized enzyme can be accounted for using standard additions, an approach used here in the determination of serum glucose.

Development of multianalyte sensor arrays composed of chemically derivatized polymeric microspheres localized in micromachined cavities

The development of a chip-based sensor array composed of individually addressable polystyrene-poly(ethylene glycol) and agarose microspheres has been demonstrated. The microspheres are selectively arranged in micromachined cavities localized on silicon wafers. These cavities are created with an anisotropic etch and serve as miniaturized reaction vessels and analysis chambers. A single drop of fluid provides sufficient analysis media to complete approximately 100 assays in these microetch pits. The cavities possess pyramidal pit shapes with trans-wafer openings that allows for both fluid flow through the microreactors/analysis chambers and optical access to the chemically sensitive microspheres. Identification and quantitation of analytes occurs via colorimetric and fluorescence changes to receptor and indicator molecules that are covalently attached to termination sites on the polymeric microspheres. Spectral data are extracted from the array efficiently using a charge-coupled device allowing for the near-real-time digital analysis of complex fluids. The power and utility of this new microbead array detection methodology is demonstrated here for the analysis of complex fluids containing a variety of important classes of analytes including acids, bases, metal cations, metabolic cofactors, and antibody reagents.

The effect on bioadhesive polymers either freely in solution or covalently attached to a support on human macrophages

Cell surface adhesion receptors interact with a family of adhesion molecules known as integrins. It is assumed that the cells recognize and bind a specific amino acid sequence. It is likely that the host inflammatory response may be mediated via the recognition of the inflammatory cells with the specific integrin molecules. The mechanism of such behavior has not been fully elucidated. This investigation was designed to provide more insight regarding the cellular response associated with incubation of macrophages with polymers either freely in solution or adhered to surfaces. Peripheral macrophages were seeded at a density of 4 x 10(6) cells on supports coated with either amino-acid heteropolymers of RGE, RGD, or amino-acid homopolymer Poly-L-lysine. Cells were also seeded at the same density in 24 well plates and the wells were treated with RGD, RGE or Poly-L-lysine. The cells were examined morphologically and biochemically at 24, 48, and 72 hours. The results showed cells growing on supports coated with RGD had significantly (p < 0.05) higher numbers of cells adhering and remaining viable, in comparison to cells growing on Poly-L-lysine or RGE supports. Cells growing on supports coated with RGE appeared irregularly (elongated and spindle) shaped and unevenly spaced. The cells growing on Poly-L-Lysine coated supports showed cellular disruption and lysis, whereas cells growing on the RGD appeared intact, regularly spaced and began fusing into giant cells. Lactate dehydrogenase activity was used as a measure of membrane integrity, and cells grown on coated supports with Poly-L lysine showed a two-fold increase in activity over control and peptide treated groups. On the other hand, cells growing in media containing the free RGE, RGD and Poly-L-lysine showed no statistical differences in cell number, and did not show increased activity of LDH for the entire duration of the experiment. The data suggests that the RGD, RGE and Poly-L-lysine dissolved in solution are highly biocompatible to the macrophages. However, when they are attached to a support they can affect cellular adherence as well as cellular activation.

Biochemical markers evaluation of RAW transformed cells during treatment with various biomaterials

Upon introduction into the human body, biomaterials initially trigger a foreign-body inflammatory response. Furthermore, the wear debris associated with such materials as those used for orthopedic implants, artificial heart valves, and dental implants can cause the body to mount an inflammatory response. This involves the production of phagocytic macrophages that ingest the foreign material while simultaneously producing cytokines that serve as chemotactic agents for an amplified immune response. Currently titanium (Ti), polyethylene (PE), tricalcium phosphate (TCP) and hydroxyapatite (HA) are widely used as biomaterials in medical implants, and particle size is an important factor in the development of orthopedic, dental, and medical implants. The objective of this study was to investigate the effect of various biomaterials (Ti, mixed particle size polyethylene (MPE), ultra high molecular weight polyethylene (UHMWPE), mixed particle size TCP (MTCP), < 0.38 micron TCP (S-TCP), and hydroxyapatite (HA)) on the inflammatory reactions expressed by transformed RAW macrophages. RAW transformed monocytes were obtained from the American Cell Culture Line, (Rockville, MD). The cells were allowed to incubate in contact with the materials for intervals of 24, 48, and 72 hours. Biochemical tests and morphological evaluations were performed after each time point, including screening for cell number, cell protein levels, supernatant protein levels, lactate dehydrogenase (LDH), Maliondialdehyde (MDA), catalase by following standard lab protocols.