Surface microtopography construction and osteogenic properties evaluation of bulk polylactic acid implants

In this study, polylactic acid (PLA) microspheres were used as the raw material to construct bulk implants with surface microtopography through hot pressing and heat treatment, and the microtopographical structures were regulated through the sizes of the PLA microspheres. The surface microtopographies of PLA implants were successfully constructed using micron-sized bulges, which showed a wave-like structure. The ridge width of bulges ranged from 1.64 ± 0.16 µm to 82.52 ± 14.38 µm and the valley depth ranged from 0.49 ± 0.07 µm to 37.35 ± 6.78 µm according to the sizes of microspheres. The nanoindentation tests showed that the modulus and hardness of PLA implants were gradually increased with the decrease in microsphere sizes. The surface microtopography resulted in a slight increase in the hydrophobicity of the PLA implants, but no significant differences were observed. Cells cultured on the implant surface with microtopography exhibited varying morphological responses, and significantly increased osteogenic activity was observed relative to a PLA flat film. This study demonstrated that the surface microtopography derived from PLA microspheres could regulate cellular response and activate osteogenic properties of PLA implants.

Prediction for 2-Year Vision Outcomes Using Early Morphologic and Functional Responses in the Comparison of Age-related Macular Degeneration Treatments Trials

OBJECTIVE

To predict 2-year visual acuity (VA) responses to anti-VEGF therapy, using early morphologic and functional responses in patients with neovascular age-related macular degeneration (nAMD).

DESIGN

Cohort within a randomized clinical trial.

PARTICIPANTS

A total of 1185 participants with untreated active nAMD and best-corrected visual acuity (BCVA) 20/25 to 20/320 at baseline.

METHODS

Secondary analysis of data from participants randomized to either ranibizumab or bevacizumab and to 1 of 3 dosing regimens. Associations of 2-year BCVA responses with baseline morphologic and functional characteristics and their change from baseline at 3 months were assessed, using univariable and multivariable linear regression models for BCVA change and logistic regression models for ≥ 3-line BCVA gain from baseline. The performance of predictions for 2-year BCVA outcomes using these characteristics was assessed using R² for BCVA change and area under the receiver operating characteristic curve (AUC) for ≥ 3-line BCVA gain.

MAIN OUTCOME MEASURES

Best-corrected visual acuity change and ≥ 3-line gain from baseline at year 2.

RESULTS

In multivariable analyses that included previously reported significant baseline predictors (baseline BCVA, baseline macular atrophy, baseline retinal pigment epithelium elevation [RPEE], and maximum width and early BCVA change from baseline at 3 months), new RPEE occurrence at 3 months was significantly associated with more BCVA gain at 2 years (10.2 letters vs. 3.5 letters for RPEE resolved, P < 0.001), and none of the other morphologic responses at 3 months were significantly associated with BCVA responses at 2 years. These significant predictors moderately predicted 2-year BCVA gain with an R² = 0.36. Baseline BCVA and ≥ 3-line BCVA gain at 3 months predicted 2-year ≥ 3-line gain with AUC 0.83 (95% confidence interval, 0.81-0.86).

CONCLUSIONS

Most structural responses on OCT at 3 months were not independently predictive of the 2-year BCVA responses, which were associated with baseline factors and the 3-month BCVA response to anti-VEGF therapy. A combination of baseline predictors, early BCVA, and morphologic responses at 3 months only moderately predicted the long-term BCVA responses. Future research is needed to better understand the factors contributing to the variation in long-term vision outcomes with anti-VEGF therapy.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found after the references.

Morphological and physiological responses of Dianthus spiculifolius high wax mutant to low-temperature stress

Cuticular wax plays a role in plant responses to environmental stresses. To understand the contribution of cuticular wax to plant responses to low-temperature stress, the morphological and physiological responses of a Dianthus spiculifolius high-wax (HW) mutant and wild type (WT) were compared. Under low-temperature stress (0 and -10 °C), HW plants showed a lower mortality rate and electrolyte leakage (El) than that WT plants. In plants treated with low-temperature stress (0 and -10 °C), HW mutant leaves exhibited higher soluble sugar and free proline contents and lower malondialdehyde contents than those WT leaves. The photosynthetic capacity, net photosynthetic rate, stomatal conductance, and maximal photochemical efficiency of photosystem II in HW mutant leaves were the least inhibited by low temperature than those in WT leaves. The dewaxing experiments showed no significant difference in the phenotype and El between the dewaxed-treated HW mutant and WT leaves under low-temperatures stress, indicating that cuticular wax causes differences in resistance to low-temperatures between HW and WT. Principal component analysis and the membership function value of the physiological data showed that the average membership value of the HW mutant was greater than that in WT. In general, the results indicated that high cuticular wax contributes positively to the response to low-temperature stress by D. spiculifolius.

Uptake of a plasticizer (di-n-butyl phthalate) impacts the biochemical and physiological responses of barley

BACKGROUND

DBP is one of the most commonly used plasticizers for imparting desirable properties to polymers. The introduction of phthalates is reported to have occurred in the late 1920s, and there has been a significant rise in their release into the environment in past decades due to a lack of covalent bonding with the parent matrix. Because of their numerous applications in day-to-day life, phthalates have become ubiquitous and also classified as endocrine disruptors. Hence, several studies have been conducted to investigate the phthalate-mediated toxicities in animals; however, plants have not been explored to the same amount.

METHODS

Therefore, in the present study, the accumulation and translocation along with morpho-physiological perturbations in barley plants after 15, 30, 60, and 120 days of exposure to di-n-butyl phthalate (DBP) are investigated using standard protocols.

RESULTS

The maximal accumulation and translocation of DBP in the roots and shoots of barley plants was observed after 60 days of exposure. The exposure of DBP from 15 to 120 days was recorded to decline all the morphological indices (i.e., dry weight, net primary productivity, seed number per spike, and seed weight) of barley plants. The pigments content declined under DBP treatment for all exposure durations except 120 days exposure. Carbohydrate content increased after 15-30 days of exposure afterward it was observed to be decreased under 60 and 120 days of exposure. The protein content was declined in DBP stressed plants for 15-120 days. Proline content was increased in all exposure durations and maximal percent increase was recorded in 120 days of exposure. MDA content showed an increase at earlier exposure durations then followed by a decline in long-term exposure. Hydrogen peroxide content increased at all exposure durations. There were significant alterations observed in the activities of all antioxidative enzymes in comparison to the control. Furthermore, DBP stressed plants after 60 days were analyzed for the macromolecular variations using Fourier transform infrared spectroscopy (FTIR).

CONCLUSION

Thus, the outcomes of the current work provide an appraisal of phthalates' uptake and translocation mediated phytotoxic responses in barley plants. These observations can help in developing genetically modified edible plants that are resistant to phthalates uptake, thereby ensuring food security.

Effects of glyphosate on hepatic tissue evaluating melanomacrophages and erythrocytes responses in neotropical anuran Leptodactylus latinasus

Glyphosate (GLY) is the most used herbicide worldwide and its effects on anurans are well known. Pollutants can cause physiological and morphological effects. Therefore, this study evaluated the effects of GLY on hepatic melanomacrophages as a response to environmental stressors. Three treatments were exposed to different concentrations of pure GLY (100, 1000, and 10,000 μg g(-1), respectively), and there was also a control group. After the experimental time, liver and blood were analyzed. Melanomacrophages (MMCs) were located between the hepatocyte cordons, close to sinusoids. GLY increased the melanin area in MMCs of Leptodactylus latinasus exposed since lowest concentration until highest concentration. GLY also changed the occurrence of hepatic catabolism pigments into melanomacrophages and erythrocyte nuclear abnormalities; therefore, it can interfere with the hepatic metabolism. In conclusion, GLY promotes alterations in the hepatic tissue and erythrocyte nuclear abnormalities. Furthermore, MMCs may be useful as morphological responses of GLY effects.