PLLA

Poly L(+) lactic acid (PLLA) has become crucial in the biomedical industry for various uses. The direct polycondensation method was used to prepare Poly L(+) Lactic Acid (PLLA). Different catalysts, including metal oxides and metal halides, were used to test the polymerization technique. The effect of the amount of catalysts and the type of coupling agent were investigated. The effect of reaction time and polymerization solvents was also studied. PLLA was loaded with isosorbide dinitrate utilizing the solvent evaporation process...

Radical prostatectomy (RP) can cause neurogenic erectile dysfunction (ED), which negatively affects the quality of life of patients with prostate cancer. Currently, there is a dearth of effective therapeutic strategies. Although stem cell therapy is promising, direct cell transplantation to injured cavernous nerves is constrained by poor cell colonization. In this study, poly-L-lactic acid (PLLA)/gelatin electrospun membranes (PGEM) were fabricated to load bone marrow-derived mesenchymal stem cells (BM-MSCs) as a patch to be placed on injured nerves to alleviate ED...

Safe-and-sustainable-by-design (SSbD) nanomaterials (NMs) or NM-containing products are a priority. Silver (Ag) NMs have a vast array of applications, including biomedical and other products, even as nanopesticides. Thus, their release to the environment is expected to increase. The aim of the present study was to assess the ecotoxicity of the SSbD Ag NM to the soil model species Enchytraeus crypticus (Oligochaeta). The Ag NM tested consists in a SSbD Ag with biomedical applications, a hydroxyethyl cellulose (HEC) coated Ag NMs (AgHEC) and its toxicity was compared to the naked Ag NMs (Ag-Sigma), an Ag-based biomedical product (PLLA-Ag: Poly l-Lactide microfibers doped with Ag), and AgNO3 ...

INTRODUCTION: Facial aging has long been an area of focus in esthetic surgery. It is the consequence of physiologic and environmental factors, with a trend toward non-surgical modalities. Although volume augmentation has long been a focus of non-surgical facial rejuvenation, there is emerging interest in the use of biostimulators to induce physiologic changes in the skin. This article aimed to provide an overview of this class of therapies. METHODS: A systematic review regarding the clinical use of biostimulatory agents including platelet-rich plasma (PRP), platelet-rich fibrin (PRF), poly-L-lactic acid (PLLA) and calcium hydroxylapatite (CaHA) in facial rejuvenation was performed using PubMed databases...

Pelvic organ prolapse (POP) is one of the most common pelvic floor dysfunction disorders worldwide. The weakening of pelvic connective tissues initiated by excessive collagen degradation is a leading cause of POP. However, the patches currently used in the clinic trigger an unfavorable inflammatory response, which often leads to implantation failure and the inability to simultaneously reverse progressive collagen degradation. Therefore, to overcome the present challenges, a new strategy is applied by introducing puerarin (Pue) into poly(l-lactic acid) (PLLA) using electrospinning technology...

OBJECTIVE: To explore the effect of NaOH on the surface morphology of three-dimensional (3D) printed poly- L -lactic acid (PLLA) mesh scaffolds. METHODS: The 3D printed PLLA mesh scaffolds were prepared by fused deposition molding technology, then the scaffold surfaces were etched with the NaOH solution. The concentrations of NaOH solution were 0.01, 0.1, 0.5, 1.0, and 3.0 mol/L, and the treatment time was 1, 3, 6, 9, and 12 hours, respectively. There were a total of 25 concentration and time combinations...

The preparation of bio-based poly(lactic acid) (PLA) foams with high mechanical properties and heat resistance is of great significance for environmental protection and green sustainable development. In this paper, D-sorbitol (DS) containing six hydroxyl groups was introduced into poly(l-lactide) (PLLA)/poly(d-lactide) (PDLA) blends for first time to promote the formation of stereocomplex (SC) crystals, which could improve the foaming behavior and enhance mechanical properties and heat resistance of PLA foams...

GRAND FIX mesh-type plates and pins (Gunze, Kyoto, Japan) are thin, bioabsorbable fixation devices made of poly-L-lactide (PLLA) composite. These devices are new, and how best to use them in clinical practice remains to be determined. Thus, we describe our approach to rib fixation after thoracotomy in an aortic surgery using GRAND FIX mesh-type plates and pins. The advantage of our approach is that it is easy to perform, but careful attention should be paid to fix the ribs appropriately.

Poly-L-lactin acid (PLLA) has been widely used in the field of bio-medicine. In 2004, as an injectable material, PLLA was approved by the FDA to treat AIDS-related facial atrophy. Since then, several injectable stuffs containing PLLA have been approved for marketing in various countries and regions. Recently, PLLA has often been used to treat facial rejuvenation problems like cutaneous depressions and static wrinkles which always induce unsatisfactory facial expression. This review introduces the physicochemical properties, regeneration stimulating mechanism, applications in aesthetics and injectable comorbidity of PLLA...

BACKGROUND: Poly(L-lactic acid) (PLLA) is a biodegradable polymer (BP) that replaces conventional petroleum-based polymers.  The hydrophobicity of biodegradable PLLA periodontal barrier membrane in wet state can be solved by alloying it with natural polymers. Alloying PLLA with gelatin imparts wet mechanical properties, hydrophilicity, shrinkage, degradability and biocompatibility to the polymeric matrix. METHODS: To investigate membrane performance in the wet state, PLLA/gelatin membranes were synthesized by varying the gelatin concentration from 0 to 80 wt%...

Solvent evaporation is one of the most fundamental processes in soft matter. Structures formed via solvent evaporation are often complex yet tunable via the competition between solute diffusion and solvent evaporation time scales. This work concerns the polymer evaporative crystallization on the water surface (ECWS). The dynamic and two-dimensional (2D) nature of the water surface offers a unique way to control the crystallization pathway of polymeric materials. Using poly(l-lactic acid) (PLLA) as the model polymer, we demonstrate that both one-dimensional (1D) crystalline filaments and two-dimensional (2D) lamellae are formed via ECWS, in stark contrast to the 2D Langmuir-Blodgett monolayer systems as well as polymer solution crystallization...

Lycorine is a kind of natural active ingredient with a strong antitumor effect. In this study, folate ligand-conjugated polyethylene glycol-block-poly(l-lactide) (PEG-PLLA) nanoparticles (FA-PEG-PLLA NPs) were designed to deliver lycorine to enhance its anti-glioma activity. The successful preparation of the FA-PEG-PLLA polymer was confirmed by 1 H-NMR, FT-IR, XRD, TGA, and DSC. The optimal formulation for LYC@FA-PEG-PLLA NPs was determined by response surface analysis as follows: sodium dodecyl sulfate (SDS) of 1%, carrier material of 0...

Cuprous oxide (Cu2 O) has great potential in photodynamic therapy for implant-associated infections due to its good biocompatibility and photoelectric properties. Nevertheless, the rapid recombination of electrons and holes weakens its photodynamic antibacterial effect. In this work, a new nanosystem (Cu2 O@rGO) with excellent photodynamic performance was designed via the in situ growth of Cu2 O on reduced graphene oxide (rGO). Specifically, rGO with lower Fermi levels served as an electron trap to capture photoexcited electrons from Cu2 O, thereby promoting electron-hole separation...

Polymeric nanoparticles (PNPs) are frequently researched and used in drug delivery. The degradation of PNPs is highly dependent on various properties, such as polymer chemical structure, size, crystallinity, and melting temperature. Hence, a precise understanding of PNP degradation behavior is essential for optimizing the system. This study focused on enzymatic hydrolysis as a degradation mechanism by investigation of the degradation of PNP with various crystallinities. The aliphatic polyester polylactide ([C3 H4 O2 ]n, PLA) was used as two chiral forms, poly l-lactide (PlLA) and poly d-lactide (PdLA), and formed a unique crystalline stereocomplex (SC)...

We have operated on two cases of slipped ribs syndrome( SRS). Both patients were men in their 40s with a history of right thoracic trauma who were referred to us because of unexplained lower thoracic pain. The left rib was positive for hooking maneuver (lift test), and dynamic ultrasonography showed narrowing of the intercostal space, which led to the diagnosis of SRS. in the first case, the tip of the ninth rib cartilage was excised, and the ninth and tenth rib cartilages were sutured and fixed with No.2 fiber wire in two places with Z sutures...

OBJECTIVE: Mesenchymal stem cells (MSCs) are widely recognized as a promising cell type for therapeutic applications due to their ability to secrete and regenerate bioactive molecules. For effective bone healing, it is crucial to select a scaffold that can support, induce, and restore biological function. Evaluating the scaffold should involve assessing MSC survival, proliferation, and differentiation. The principal aim of this investigation was to formulate composite nanofibrous scaffolds apt for applications in bone tissue engineering...

Minimally invasive surgery procedures are of utmost relevance in clinical practice. However, the associated mechanical stress on the material poses a challenge for new implant developments. In particular PLLA, one of the most widely used polymeric biomaterials, is limited in its application due to its high brittleness and low elasticity. In this context, blending is a conventional method of improving the performance of polymer materials. However, in implant applications and development, material selection is usually limited to the use of medical grade polymers...

Natural bone exhibits a complex anisotropic and micro-nano hierarchical structure, more importantly, bone extracellular matrix (ECM) presents liquid crystal (LC) phase and viscoelastic characteristics, providing a unique microenvironment for guiding cell behavior and regulating osteogenesis. However, in bone tissue engineering scaffolds, the construction of bone-like ECM microenvironment with exquisite microstructure is still a great challenge. Here, we developed a novel polysaccharide LC hydrogel supported 3D printed poly(l-lactide) (PLLA) scaffold with bone-like ECM microenvironment and micro-nano aligned structure...

In order to solve the problem of uneven microporous structure of Poly(L-lactic acid) (PLLA) bulk orientation by using biological safety multi-functional plant oil as chain extenders (CE), multi-armed flexible chains were introduced into PLLA through reactive processing to prepare long chain branched PLLA (LCB-PLLA). When the total content of the CE was 6.15 wt%, PLLA and the CE reacted most fully, while maintaining the tensile strength of PLLA and improving toughness. After introducing the LCB structure, the presence of multi-armed flexible chains increased the mobility of the molecular chains, resulting in a significantly lower degree of crystallinity...

Bone implantation inevitably causes damage to surrounding vasculature, resulting in a hypoxic microenvironment that hinders bone regeneration. Although titanium (Ti)-based devices are widely used as bone implants, their inherent bioinert surface leads to poor osteointegration. Herein, a strontium peroxide (SrO2 )-decorated Ti implant, Ti_P@SrO2 , was constructed through coating with poly-L-lactic acid (PLLA) to alleviate the hypoxic microenvironment and transform the bioinert surface of the implant into a bioactive surface...