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Micromachines Jun 2024Polylactic acid (PLA) is a biobased, biodegradable, non-toxic polymer widely considered for replacing traditional petroleum-based polymer materials. Being a... (Review)
Review
Polylactic acid (PLA) is a biobased, biodegradable, non-toxic polymer widely considered for replacing traditional petroleum-based polymer materials. Being a semi-crystalline material, PLA has great potential in many fields, such as medical implants, drug delivery systems, etc. However, the slow crystallization rate of PLA limited the application and efficient fabrication of highly crystallized PLA products. This review paper investigated and summarized the influence of formulation, compounding, and processing on PLA's crystallization behaviors and mechanical performances. The paper reviewed the literature from different studies regarding the impact of these factors on critical crystallization parameters, such as the degree of crystallinity, crystallization rate, crystalline morphology, and mechanical properties, such as tensile strength, modulus, elongation, and impact resistance. Understanding the impact of the factors on crystallization and mechanical properties is critical for PLA processing technology innovations to meet the requirements of various applications of PLA.
PubMed: 38930746
DOI: 10.3390/mi15060776 -
Bioengineering (Basel, Switzerland) May 2024Although the incidence of infections in orthopedic surgeries, including periprosthetic surgeries, remains low at approximately 1-2%, the number of surgeries and the...
Although the incidence of infections in orthopedic surgeries, including periprosthetic surgeries, remains low at approximately 1-2%, the number of surgeries and the incidence of drug-resistant bacteria is increasing. The cost and morbidity associated with revision surgeries are huge. More effective drug combinations and delivery methods are urgently needed. In this paper, three anti-infective drugs (vancomycin, rifampicin, and silver sulfadiazine) have been jointly and effectively electrospun in thin (0.1 mm) flexible nanofiber mats of either poly (methyl methacrylate) (PMMA) or poly (lactic-co-glycolic acid) (PLGA). The inclusion of poly (ethylene glycol) (PEG) enabled optimal drug release with a reduced water contact angle for wetting. The controlled release of these three agents from 20% PEG (/ to polymer)-blended PMMA or PLGA nanofiber mats may allow for the prophylactical prevention of implant-related infections or provide methods to treat orthopedic infections at the time of revision surgeries. These combinations of drugs provide excellent additive or synergistic antibiotic action against a broader spectrum of bacteria than each drug alone.
PubMed: 38927765
DOI: 10.3390/bioengineering11060529 -
Biomolecules Jun 2024Osteoblastic responses play a crucial role in the success of oral implants. Enhanced proliferation of osteoblast cells is associated with reduced cell mortality and an... (Comparative Study)
Comparative Study
INTRODUCTION
Osteoblastic responses play a crucial role in the success of oral implants. Enhanced proliferation of osteoblast cells is associated with reduced cell mortality and an increase in bone regeneration. This study aims to evaluate the osteoblastic responses following oral implantation.
MATERIALS AND METHODS
Osteoblast stem cells were harvested and subsequently cultivated using cell culture techniques. The osteoblastic phenotype of the extracted cells was confirmed by examining the extracellular matrix. Cell morphogenesis on functionalized biomaterial surfaces was assessed through indirect immunofluorescence staining. The cellular response was investigated in the presence of two types of implant materials: titanium (Ti) and alumina-toughened zirconia (ATZ). Cell viability and apoptosis were quantitatively assessed using MTT assays and flow cytometry, respectively.
RESULTS
The survival of osteoblastic lineage cells was moderately reduced post-implantation. Viability in the Ti implant group remained at approximately 86%, while in the ATZ group, it was observed at 75%, which is considered acceptable. Moreover, there was a significant disparity in cell survival between the two implant groups ( < 0.05). Analysis of apoptosis levels at various concentrations revealed that the rate of apoptosis was 3.6% in the control group and 18.5% in the ATZ group, indicating that apoptosis or programmed cell death in the ATZ-treated group had increased nearly four-fold ( < 0.05).
CONCLUSIONS
The findings of this study indicate a reduction in osteoblastic cell line survival following implant treatment, with titanium implants exhibiting superior performance in terms of cell survival. However, it was also noted that the incidence of apoptosis in osteoblast cells was significantly higher in the presence of zirconium-based implants.
Topics: Zirconium; Titanium; Osteoblasts; Aluminum Oxide; Cell Survival; Apoptosis; Animals; Dental Implants; Humans; Cell Proliferation; Cells, Cultured; Surface Properties
PubMed: 38927122
DOI: 10.3390/biom14060719 -
Ceska a Slovenska Oftalmologie :... 2024The aim of this study was to evaluate the outcomes of Ozurdex® (DEX) implant in patients with diabetic macular edema (DME) in real-world clinical practice, and to...
OBJECTIVE
The aim of this study was to evaluate the outcomes of Ozurdex® (DEX) implant in patients with diabetic macular edema (DME) in real-world clinical practice, and to determine the correlation between known OCT biomarkers and the effect of treatment.
MATERIAL AND METHODS
This retrospective study included 42 eyes of 33 patients (16 women, 17 men) treated with DEX at the Department of Ophthalmology, Faculty of Medicine and Dentistry of Palacký University and University Hospital Olomouc for DME indication between 2020 and 2023. Follow-up examinations were conducted at 1, 3, and 6 months after the first DEX application. The main assessed parameters were: best-corrected visual acuity (BCVA), intraocular pressure (IOP), central retinal thickness (CRT), OCT biomarkers. The results were subsequently statistically evaluated.
RESULTS
At the first follow-up after DEX application, there was an average decrease in CRT of 186 ±146µm and a gain of 3 ±7 letters. Positive morphological and functional responses were observed in 39 eyes (92.9%) and 23 eyes (54.8%) respectively. The disorganization of retinal inner layers (DRIL) biomarker was initially present in 41 eyes (97.6%), with reduction or disappearance observed in 13 eyes (31%) post-application. Eyes with ellipsoid zone disruption (EZ disruption) had an average initial BCVA of 49.6 letters, compared to 57.8 letters in the group without this biomarker. The mean gain in BCVA was +8.7 letters in treatment-naive eyes and +2.1 letters in previously treated eyes. Chronic DME was less frequent in treatment-naive (n = 1, 14.3%) compared to previously treated eyes (n = 28, 84.8%). All these results were statistically significant (p < 0.05). An increase in IOP post-DEX application occurred in 9 patients (21.4%).
CONCLUSION
Our results confirm DEX as a safe and effective treatment option for DME. Treatment-naive patients achieved better functional outcomes. We confirmed ellipsoid zone disruption (EZ disruption) as a negative biomarker. Additionally, we demonstrated the capacity of DEX to reduce disorganization of the retinal inner layers (DRIL).
Topics: Humans; Macular Edema; Male; Female; Diabetic Retinopathy; Dexamethasone; Retrospective Studies; Middle Aged; Aged; Intravitreal Injections; Drug Implants; Visual Acuity; Glucocorticoids; Tomography, Optical Coherence
PubMed: 38925895
DOI: 10.31348/2024/29 -
Microbial Pathogenesis Jun 2024Increasing incidences of fungal infections and prevailing antifungal resistance in healthcare settings has given rise to an antifungal crisis on a global scale. The...
Increasing incidences of fungal infections and prevailing antifungal resistance in healthcare settings has given rise to an antifungal crisis on a global scale. The members of the genus Candida, owing to their ability to acquire sessile growth, are primarily associated with superficial to invasive fungal infections, including the implant-associated infections. The present study introduces a novel approach to combat the sessile/biofilm growth of Candida by fabricating nanofibers using a nanoencapsulation approach. This technique involves the synthesis of tyrosol (TYS) functionalized chitosan gold nanocomposite, which is then encapsulated into PVA/AG polymeric matrix using electrospinning. The FESEM, FTIR analysis of prepared TYS-AuNP@PVA/AG NF suggested the successful encapsulation of TYS into the nanofibers. Further, the sustained and long-term stability of TYS in the medium was confirmed by drug release and storage stability studies. The prepared nanomats can absorb the fluid, as evidenced by the swelling index of the nanofibers. The growth and biofilm inhibition, as well as the disintegration studies against Candida, showed 60-70 % biofilm disintegration when 10 mg of TYS-AuNP@PVA/AG NF was used, hence confirming its biological effectiveness. Subsequently, the nanofibers considerably reduced the hydrophobicity index and ergosterol content of the treated cells. Considering the challenges associated with the inhibition/disruption of fungal biofilm, the fabricated nanofibers prove their effectiveness against Candida biofilm. Therefore, nanocomposite-loaded nanofibers have emerged as potential materials that can control fungal colonization and could also promote healing.
PubMed: 38925344
DOI: 10.1016/j.micpath.2024.106763 -
Journal of Biomedical Materials... Jul 2024Hydroxyapatites (HAps) synthesized from waste animal bones have recently gained attention due to their outstanding properties. This is because there is a need to... (Review)
Review
Hydroxyapatites (HAps) synthesized from waste animal bones have recently gained attention due to their outstanding properties. This is because there is a need to fabricate scaffolds with desirable mechanical strength, ability to withstand high temperatures, and insoluble in solvents such as water, acetone, ethanol, and isopropyl alcohol. This study is an extensive summary of many articles on the routes of synthesis/preparation of HAp, and the optimum processing parameter, and the biomedical application areas, such as: drug administration, dental implants, bone tissue engineering, orthopedic implant coatings, and tissue regeneration/wound healing. A broad catalog of the synthesis methods (and combination methods), temperature/time, shape/size, and the calcium-to-phosphorous (Ca/P) value of diverse waste animal bone sources were reported. The alkaline hydrolysis method is proposed to be suitable for synthesizing HAp from natural sources due to the technique's ability to produce intrinsic HAp. The method is also preferred to the calcination method owing to the phase transformation that takes place at high temperatures during calcinations. However, calcinations aid in removing impurities and germs during heating at high temperatures. When compared to calcination technique, alkaline hydrolysis method results in crystalline HAp; the higher degree of crystallinity is disadvantageous to HAp bioactivity. In addition, the standardization and removal of impurities and contaminants, thorough biocompatibility to ensure clinical safety of the HAp to the human body, and improvement of the mechanical strength and toughness to match specific requirements for the various biomedical applications are the important areas for future studies.
Topics: Animals; Durapatite; Bone and Bones; Humans; Tissue Engineering; Bone Substitutes; Tissue Scaffolds
PubMed: 38923882
DOI: 10.1002/jbm.b.35440 -
Journal of Applied Oral Science :... 2024to evaluate the morphological and functional characteristics of the peri-implant bone tissue that was formed during the healing process by the placement implants using...
OBJECTIVES
to evaluate the morphological and functional characteristics of the peri-implant bone tissue that was formed during the healing process by the placement implants using two different surface treatments: hydrophilic Acqua™ (ACQ) and rough NeoPoros™ (NEO), in spontaneously hypertensive (SHR) and normotensive rats (Wistar) whether or not treated with losartan.
METHODOLOGY
In total, 96 male rats (48 Wistar and 48 SHR) were divided into eight subgroups: absolute control rough (COA NEO), absolute control hydrophilic (COA ACQ), losartan control rough (COL NEO), losartan control hydrophilic (COL ACQ), SHR absolute rough (SHR NEO), SHR absolute hydrophilic (SHR ACQ), SHR losartan rough (SHRL NEO), and SHR losartan hydrophilic (SHRL ACQ). The rats medicated with losartan received daily doses of the medication. NeoPoros™ and Acqua™ implants were installed in the tibiae of the rats. After 14 and 42 days of the surgery, the fluorochromes calcein and alizarin were injected in the rats. The animals were euthanized 67 days after treatment. The collected samples were analyzed by immunohistochemistry, biomechanics, microcomputerized tomography, and laser confocal scanning microscopy analysis.
RESULTS
The osteocalcin (OC) and vascular endothelium growth factor (VEGF) proteins had moderate expression in the SHRL ACQ subgroup. The same subgroup also had the highest implant removal torque. Regarding microarchitectural characteristics, a greater number of trabeculae was noted in the control animals that were treated with losartan. In the bone mineralization activity, it was observed that the Acqua™ surface triggered higher values of MAR (mineral apposition rate) in the COA, COL, and SHRL groups (p<0.05).
CONCLUSION
the two implant surface types showed similar responses regarding the characteristics of the peri-implant bone tissue, even though the ACQ surface seems to improve the early stages of osseointegration.
Topics: Animals; Losartan; Rats, Inbred SHR; Rats, Wistar; Male; Surface Properties; Dental Implants; Time Factors; X-Ray Microtomography; Reproducibility of Results; Immunohistochemistry; Hydrophobic and Hydrophilic Interactions; Osseointegration; Treatment Outcome; Dental Implantation, Endosseous; Microscopy, Confocal; Tibia; Analysis of Variance; Biomechanical Phenomena; Reference Values; Osteocalcin
PubMed: 38922240
DOI: 10.1590/1678-7757-2023-0374 -
Gels (Basel, Switzerland) May 2024Vascularized organs hold potential for various applications, such as organ transplantation, drug screening, and pathological model establishment. Nevertheless, the in...
Vascularized organs hold potential for various applications, such as organ transplantation, drug screening, and pathological model establishment. Nevertheless, the in vitro construction of such organs encounters many challenges, including the incorporation of intricate vascular networks, the regulation of blood vessel connectivity, and the degree of endothelialization within the inner cavities. Natural polymeric hydrogels, such as gelatin and alginate, have been widely used in three-dimensional (3D) bioprinting since 2005. However, a significant disparity exists between the mechanical properties of the hydrogel materials and those of human soft tissues, necessitating the enhancement of their mechanical properties through modifications or crosslinking. In this study, we aim to enhance the structural stability of gelatin-alginate hydrogels by crosslinking gelatin molecules with oxidized pullulan (i.e., a polysaccharide) and alginate molecules with calcium chloride (CaCl). A continuous small-diameter vascular network with an average outer diameter of 1 mm and an endothelialized inner surface is constructed by printing the cell-laden hydrogels as bioinks using a coaxial 3D bioprinter. The findings demonstrate that the single oxidized pullulan crosslinked gelatin and oxidized pullulan/CaCl double-crosslinked gelatin-alginate hydrogels both exhibit a superior structural stability compared to their origins and CaCl solely crosslinked gelatin-alginate hydrogels. Moreover, the innovative gelatin and gelatin-alginate hydrogels, which have excellent biocompatibilities and very low prices compared with other hydrogels, can be used directly for tissue/organ construction, tissue/organ repairment, and cell/drug transportation.
PubMed: 38920913
DOI: 10.3390/gels10060366 -
Pediatrics Jul 2024Surgery is one of the most common indications for opioid prescribing to pediatric patients. We identified which procedures account for the most pediatric surgical opioid...
BACKGROUND AND OBJECTIVES
Surgery is one of the most common indications for opioid prescribing to pediatric patients. We identified which procedures account for the most pediatric surgical opioid prescribing.
METHODS
We conducted a cross-sectional analysis of commercial and Medicaid claims in the Merative MarketScan Commercial and Multi-State Medicaid Databases. Analyses included surgical procedures for patients aged 0 to 21 years from December 1, 2020, to November 30, 2021. Procedures were identified using a novel crosswalk between 3664 procedure codes and 1082 procedure types. For each procedure type in the crosswalk, we calculated the total amount of opioids in prescriptions dispensed within 3 days of discharge from surgery, as measured in morphine milligram equivalents (MMEs). We then calculated the share of all MMEs accounted for by each procedure type. We conducted analyses separately among patients aged 0 to 11 and 12 to 21 years.
RESULTS
Among 107 597 procedures for patients aged 0 to 11 years, the top 3 procedures accounted for 59.1% of MMEs in opioid prescriptions dispensed after surgery: Tonsillectomy and/or adenoidectomy (50.3%), open treatment of upper extremity fracture (5.3%), and removal of deep implants (3.5%). Among 111 406 procedures for patients aged 12 to 21 years, the top 3 procedures accounted for 33.1% of MMEs: Tonsillectomy and/or adenoidectomy (12.7%), knee arthroscopy (12.6%), and cesarean delivery (7.8%).
CONCLUSIONS
Pediatric surgical opioid prescribing is concentrated among a small number of procedures. Targeting these procedures in opioid stewardship initiatives could help minimize the risks of opioid prescribing while maintaining effective postoperative pain control.
Topics: Humans; Child; Adolescent; Child, Preschool; Analgesics, Opioid; Infant; Cross-Sectional Studies; Pain, Postoperative; Practice Patterns, Physicians'; Young Adult; Female; Male; United States; Infant, Newborn; Drug Prescriptions; Surgical Procedures, Operative; Medicaid
PubMed: 38919985
DOI: 10.1542/peds.2024-065814 -
Current Pharmaceutical Biotechnology Jun 2024The trend in the incidence rate of bone fractures has been upward and as a result, the burden associated with orthopedic fractures has increased significantly. Titanium...
The trend in the incidence rate of bone fractures has been upward and as a result, the burden associated with orthopedic fractures has increased significantly. Titanium (Ti) implants are considered a preferred method of managing long bone fractures. However, no benefit comes without some downside, and using Ti implants is associated with several complications. In this respect, it was observed that in bones, Ti can disrupt the bone healing process by disturbing the balance of osteoclast and osteoblast activation and also increasing the production of inflammatory cytokines. Melatonin is a widely-acting molecule that possesses strong anti-oxidant features. This molecule reinforces mineral density and improves bone formation processes. In this review, we focused on the protective effect of melatonin in mitigating the Ti-related complications.
PubMed: 38919083
DOI: 10.2174/0113892010300967240610111644