Influence of Chemical and Physical Change of Pollen Microgels on Swelling/De-Swelling Behavior.

Pollen, the male microgametophyte of seed plants, is commonly used as a food and health supplement. Here, a facile method to transform sunflower pollen into pH-responsive microgels with tailored properties is presented. The structure and morphology of the pollen microgel are characterized by scanning electron microscopy, confocal laser scanning microscopy, and dynamic image particle analysis based on potassium hydroxide treatment with various incubation time and concentration. These pollen microgels exhibit significant volume change under different pH conditions and Ca+ /ethylenediaminetetraacetic acid treatment. The results describe the fundamental properties of pollen microgels and pave the way for its future applications, such as "smart" drug carriers.

Nonvascularized Iliac Bone Reconstruction for the Mandible Without Maxillofacial Skin Scarring.

PURPOSE: There are many methods to reconstruct the mandible, but they are often accompanied by trauma, which can lead to scarring of the maxillofacial skin. The purpose of this study was to show the utility of a minimally invasive method for reconstruction of the mandible with nonvascularized iliac bone grafts without a skin scar, as well as to evaluate the success rate and complications. PATIENTS AND METHODS: This was a retrospective case series. We retrospectively analyzed patients who underwent transoral resection of benign mandibular pathologies, followed by nonvascularized iliac bone graft reconstruction. The primary outcome variable was the success rate of the bone grafts. Secondary outcome variables were postoperative complications at the grafted bone recipient and donor sites, the long-term absorptivity of grafted bone, and the type of mandibular defect. We computed descriptive statistics or performed the χ2 test for each variable. RESULTS: Overall, 54 patients were included in the study, including 21 male and 33 female patients, with an age range of 10 to 65 years. The complete survival rate was 87.0% (47 of 54 patients), and the partial survival rate was 98.1% (53 of 54). The average bone absorption rate 3 years after surgery was 1.8 to 30.7%. We propose a new classification method for mandibular defects based on the extent of the tumor, location of the osteotomy, and degree of surgical difficulty. CONCLUSIONS: Intraoral nonvascularized iliac bone grafting is a highly successful minimally invasive method for mandibular reconstruction. It is also one of the best methods for mandibular reconstruction in patients with benign mandibular tumors without soft tissue involvement.

Transformation of hard pollen into soft matter.

Pollen's practically-indestructible shell structure has long inspired the biomimetic design of organic materials. However, there is limited understanding of how the mechanical, chemical, and adhesion properties of pollen are biologically controlled and whether strategies can be devised to manipulate pollen beyond natural performance limits. Here, we report a facile approach to transform pollen grains into soft microgel by remodeling pollen shells. Marked alterations to the pollen substructures led to environmental stimuli responsiveness, which reveal how the interplay of substructure-specific material properties dictates microgel swelling behavior. Our investigation of pollen grains from across the plant kingdom further showed that microgel formation occurs with tested pollen species from eudicot plants. Collectively, our experimental and computational results offer fundamental insights into how tuning pollen structure can cause dramatic alterations to material properties, and inspire future investigation into understanding how the material science of pollen might influence plant reproductive success.

Human blood plasma catalyses the degradation of Lycopodium plant sporoderm microcapsules.

Plant sporoderm are among the most robust biomaterials in nature. We investigate the erosion of Lycopodium sporoderm microcapsules (SDMCs) triggered by human blood plasma. Dynamic image particle analysis (DIPA), field emission scanning electron microscopy (FESEM) and Fourier transform infrared (FTIR) spectroscopy demonstrate the degradation events, suggesting bulk erosion as the dominant mechanism for SDMCs fragmentation in human blood. These results should prove valuable in discerning the behaviour of SDMCs in potential biological applications.

Species-Specific Biodegradation of Sporopollenin-Based Microcapsules.

Sporoderms, the outer layers of plant spores and pollen grains, are some of the most robust biomaterials in nature. In order to evaluate the potential of sporoderms in biomedical applications, we studied the biodegradation in simulated gastrointestinal fluid of sporoderm microcapsules (SDMCs) derived from four different plant species: lycopodium (Lycopodium clavatum L.), camellia (Camellia sinensis L.), cattail (Typha angustifolia L.), and dandelion (Taraxacum officinale L.). Dynamic image particle analysis (DIPA) and field-emission scanning electron microscopy (FE-SEM) were used to investigate the morphological characteristics of the capsules, and Fourier-transform infrared (FTIR) spectroscopy was used to evaluate their chemical properties. We found that SDMCs undergo bulk degradation in a species-dependent manner, with camellia SDMCs undergoing the most extensive degradation, and dandelion and lycopodium SDMCs being the most robust.

Extraction of cage-like sporopollenin exine capsules from dandelion pollen grains.

Pollen-based microcapsules such as hollow sporopollenin exine capsules (SECs) have emerged as excellent drug delivery and microencapsulation vehicles. To date, SECs have been extracted primarily from a wide range of natural pollen species possessing largely spherical geometries and uniform surface features. Nonetheless, exploring pollen species with more diverse architectural features could lead to new application possibilities. One promising class of candidates is dandelion pollen grains, which possess architecturally intricate, cage-like microstructures composed of robust sporopollenin biopolymers. Here, we report the successful extraction and macromolecular loading of dandelion SECs. Preservation of SEC morphology and successful removal of proteinaceous materials was evaluated using scanning electron microscopy (SEM), matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometry, elemental CHN analysis, dynamic image particle analysis (DIPA) and confocal laser scanning microscopy (CLSM). Among the tested processing schemes, acidolysis using 85% (v/v) phosphoric acid refluxed at 70 °C for 5 hours yielded an optimal balance of intact particle yield, protein removal, and preservation of cage-like microstructure. For proof-of-concept loading, bovine serum albumin (BSA) was encapsulated within the dandelion SECs with high efficiency (32.23 ± 0.33%). Overall, our findings highlight how hollow microcapsules with diverse architectural features can be readily prepared and utilized from plant-based materials.

Short Implants (5 to 8 mm) Versus Longer Implants (>8 mm) with Sinus Lifting in Atrophic Posterior Maxilla: A Meta-Analysis of RCTs.

OBJECTIVE: The specific purposes of this study were (1) to undertake a thorough systematic review and meta-analysis based only on randomized clinical trials (RCTs) to compare the rates of survival and complications of short implants to those of long implants; (2) to compare the surgical time and cost of short implants to those of long implants. METHODS: RCTs were identified from the major electronic databases (MEDLINE, Embase and Cochrane Library) using the keywords "dental implant," "short implant" and "atrophic maxilla," and a quantitative meta-analysis was conducted. The survival rate of implants and complications were the primary outcome measures, and other parameters assessed included costs and surgical time. RESULTS: Seven RCTs that met the inclusion criteria included 554 implants (265 implants in the short implant group). There was no significant difference in survival rate between two groups (RR: 1.00; 95% CI: [0.97, 1.03]; p = .96; seven trials, 554 participants). Compared with long implant group, the short implant group had a lower complications and the effect measure was significant (RR: 0.58; 95% CI: [0.37, 0.90]; p = .02; seven trials, 554 participants). CONCLUSION: This systematic review showed that no difference between the survival rates of short implants (5-8 mm) and long implants (>8 mm); complications in short implants are lower than that in long implants. However, further studies are required to substantiate our findings.

Preparation of thermoresponsive and pH-sensitivity polymer magnetic hydrogel nanospheres as anticancer drug carriers.

In this work, a novel thermo and pH responsive magnetic hydrogel nanosphere poly(N-isopropylacrylamide-co-acrylic acid)/Fe(3)O(4) (poly(NIPAAm-co-AA)/Fe(3)O(4)) has been successfully prepared. The magnetic hydrogel nanospheres with thermo and pH-sensitivity were characterized by transmission electron microscopy (TEM), dynamic light scattering (DLS), Fourier transform infrared-spectrometer (FT-IR), UV-vis absorption spectroscopy, and vibrating sample magnetometer (VSM). The magnetic hydrogel nanospheres exhibited uniform sphere structures and superparamagnetic property. Finally, the drug loading capacities and the releasing behavior of the magnetic hydrogel nanospheres were investigated with doxorubicin hydrochloride (DOX) as an anticancer drug model. The resulting magnetic hydrogel nanospheres exhibited high encapsulation efficiency (95%) to DOX under an appropriate condition. In vitro release experiments revealed that release was faster at pH 5.3 (37°C) than at pH 7.4 (25°C) or pH 7.4 (37°C). The DOX-loaded magnetic hydrogel nanospheres also showed enhanced anticancer effect compared with the free drug in vitro. These presented results suggested that the magnetic hydrogel nanospheres have a potential as tumor targeting drug carrier.