Bioactive functionalized polymer of malic acid for bone repair and muscle regeneration

Profiling of Petroselinum sativum (mill.) fuss phytoconstituents and assessment of their biocompatibility, antioxidant, anti-aging, wound healing, and antibacterial activities

Petroselinum sativum, known as parsley, is a fragrant herb that possesses a rich heritage of utilization in traditional medicinal practices. In this study, we annotated the phytocontents of the aqueous and ethanolic extracts of P. sativum and investigated their antioxidant, cytoprotective, antiaging, wound healing, and antibacterial activities. LC-MS/MS analysis of both extracts revealed the presence of 47 compounds belonging to diverse groups including organic acids, phenolic acids, and flavonoids. By MTT assay, the extracts were fully biocompatible on immortalized human keratinocytes (HaCaT) while they inhibited intracellular ROS formation (DCFDA assay) and prevented GSH depletion (DTNB assay) upon UVA exposure. In addition, the extracts were potent in inhibiting the in vitro activities of skin-related enzymes mainly elastase, tyrosinase, collagenase and hyaluronidase. Using the scratch assay, P. sativum aqueous extract significantly enhanced wound closure when compared to untreated HaCaT cells. Moreover, both extracts inhibited Pseudomonas aeruginosa's growth, reduced biofilm formation, and impaired the swimming and swarming motilities. Also, the aqueous extract was able to inhibit the production of bacterial pigments on plates. These findings strongly suggest the usefulness of P. sativum as a source of phytochemicals suitable for dermo-cosmeceutical applications.

Novel Approaches to the Establishment of Local Microenvironment from Resorbable Biomaterials in the Brain In Vitro Models

The development of brain in vitro models requires the application of novel biocompatible materials and biopolymers as scaffolds for controllable and effective cell growth and functioning. The "ideal" brain in vitro model should demonstrate the principal features of brain plasticity like synaptic transmission and remodeling, neurogenesis and angiogenesis, and changes in the metabolism associated with the establishment of new intercellular connections. Therefore, the extracellular scaffolds that are helpful in the establishment and maintenance of local microenvironments supporting brain plasticity mechanisms are of critical importance. In this review, we will focus on some carbohydrate metabolites-lactate, pyruvate, oxaloacetate, malate-that greatly contribute to the regulation of cell-to-cell communications and metabolic plasticity of brain cells and on some resorbable biopolymers that may reproduce the local microenvironment enriched in particular cell metabolites.

LC-MS/MS and GC/MS Profiling of Petroselinum sativum Hoffm. and Its Topical Application on Burn Wound Healing and Related Analgesic Potential in Rats

Parsley (Petroselinum sativum Hoffm.) is renowned for its ethnomedicinal uses including managing pain, wound, and dermal diseases. We previously highlighted the estrogenic and anti-inflammatory properties of parsley and profiled the phytochemistry of its polyphenolic fraction using HPLC-DAD. To extend our investigation, we here characterized the phytochemical composition of the hydro-ethanolic extract using LC-MS/MS and GC-MS upon silylation, and evaluated the antioxidant, analgesic, antimicrobial, and wound healing activities of its hydro-ethanolic and polyphenolic fraction. The antioxidant property was assessed using FRAP, DPPH, and TAC assays. The antimicrobial activity was tested against four wound infectious microbes (Staphylococcus aureus, Pseudomonas aeruginosa and Candida albicans). The analgesic effect was studied using acetic acid (counting the number of writhes) and formalin (recording the licking and biting times) injections while the wound healing activity was evaluated using burn model in vivo. The LC-MS/MS showed that the hydro-ethanolic contains four polyphenols (oleuropein, arbutin, myricetin, and naringin) while GC-MS revealed that it contains 20 compounds including malic acid, D-glucose, and galactofuranoside. The hydro-ethanolic (1000 mg/kg) decreased abdominal writhes (38.96%) and licking time (37.34%). It also elicited a strong antioxidant activity using DPPH method (IC₅₀ = 19.38 ± 0.15 µg/mL). Polyphenols exhibited a good antimicrobial effect (MIC = 3.125-12.5 mg/mL). Moreover, both extracts showed high wound contraction by 97.17% and 94.98%, respectively. This study provides evidence that P. sativum could serve as a source of bio-compounds exhibiting analgesic effect and their promising application in mitigating ROS-related disorders, impeding wound infections, and enhancing burn healing.

Functional biodegradable polymers via ring-opening polymerization of monomers without protective groups

Biodegradable polymers are of current interest and chemical functionality in such materials is often demanded in advanced biomedical applications. Functional groups often are not tolerated in the polymerization process of ring-opening polymerization (ROP) and therefore protective groups need to be applied. Advantageously, several orthogonally reactive functions are available, which do not demand protection during ROP. We give an insight into available, orthogonally reactive cyclic monomers and the corresponding functional synthetic and biodegradable polymers, obtained from ROP. Functionalities in the monomer are reviewed, which are tolerated by ROP without further protection and allow further post-modification of the corresponding chemically functional polymers after polymerization. Synthetic concepts to these monomers are summarized in detail, preferably using precursor molecules. Post-modification strategies for the reported functionalities are presented and selected applications highlighted.

Potent tocolytic activity of ethyl acetate fraction of Ananas comosus on rat and human uteri

The aim of this study was to investigate the tocolytic properties of Ananas comosus extract in rat and human uterine tissue in vitro and in the rat in vivo. Organ bath technique was employed to perform functional studies in vitro. The PhysioTel transmitter was implanted in SD rats to measure the changes in intrauterine pressure (IUP) in vivo. Analyses of F2 was performed using LC-HRMS. F2 produced a non-selective inhibitory response on oxytocin, prostaglandin F2α, acetylcholine and KCl. The inhibitory activity of F2 on oxytocin-induced contraction was not attenuated by propranolol, TEA, glibenclamide and indomethacin. Nω-Nitro-L-arginine, a nitric oxide synthase inhibitor, suppressed the maximal tocolytic activity of F2 by 25%. DIDS, an inhibitor of chloride channels, appeared to suppress the relaxant effect of F2. F2 suppressed the oxytocin-induced contraction in Ca²⁺ free solution. The in vivo tocolytic activity of F2 and ritodrine were observed in non-pregnant rats during the estrous stage by suppressing the frequency and amplitude of IUP peaks following intrauterine administration. Chemical analysis confirmed the involvement of citric acid in the tocolytic activity of F2. However, another less polar fraction is essential to accompany citric acid to produce such potent inhibitory response of F2. It is likely that F2 exerted tocolytic activity by multiple mechanisms, including antagonizing L-type Ca²⁺ channels, interfering with the intracellular Ca²⁺ release mechanism and releasing nitric oxide. F2 would be a promising candidate to develop as a tocolytic agent.

RGTA® or ReGeneraTing Agents mimic heparan sulfate in regenerative medicine: from concept to curing patients

The importance of extracellular matrix (ECM) integrity in maintaining normal tissue function is highlighted by numerous pathologies and situations of acute and chronic injury associated with dysregulation or destruction of ECM components. Heparan sulfate (HS) is a key component of the ECM, where it fulfils important functions associated with tissue homeostasis. Its degradation following tissue injury disrupts this delicate equilibrium and may impair the wound healing process. ReGeneraTing Agents (RGTA^®s) are polysaccharides specifically designed to replace degraded HS in injured tissues. The unique properties of RGTA^® (resistance to degradation, binding and protection of ECM structural and signaling proteins, like HS) permit the reconstruction of the ECM, restoring both structural and biochemical functions to this essential substrate, and facilitating the processes of tissue repair and regeneration. Here, we review 25 years of research surrounding this HS mimic, supporting the mode of action, pre-clinical studies and therapeutic efficacy of RGTA^® in the clinic, and discuss the potential of RGTA^® in new branches of regenerative medicine.

Preparation of Two Types of Polymeric Micelles Based on Poly(β-L-Malic Acid) for Antitumor Drug Delivery

Polymeric micelles represent an effective delivery system for poorly water-soluble anticancer drugs. In this work, two types of CPT-conjugated polymers were synthesized based on poly(β-L-malic acid) (PMLA) derivatives. Folic acid (FA) was introduced into the polymers as tumor targeting group. The micellization behaviors of these polymers and antitumor activity of different self-assembled micelles were investigated. Results indicate that poly(ethylene glycol)-poly(β-L-malic acid)-campotothecin-I (PEG-PMLA-CPT-I, P1) is a grafted copolymer, and could form star micelles in aqueous solution with a diameter of about 97 nm, also that PEG-PMLA-CPT-II (P2) is an amphiphilic block copolymer, and could form crew cut micelles with a diameter of about 76 nm. Both P1 and P2 micelles could improve the cellular uptake of CPT, especially the FA-modified micelles, while P2 micelles showed higher stability, higher drug loading efficiency, smaller size, and slower drug release rate than that of P1 micelles. These results suggested that the P2 (crew cut) micelles possess better stability than that of the P1 (star) micelles and might be a potential drug delivery system for cancer therapy.

Solubilization of water-insoluble drugs due to random amphiphilic and degradable poly(dimethylmalic acid) derivatives

Amphotericin B (AmB) and clofazimine are potent drugs hindered by their low water solubilities and their toxicities. Carriers able to increase their apparent water solubilities are needed for these drugs and for other molecules with similar properties. Random amphiphilic copolymers derived from poly(dimethylmalic acid) were obtained using different hydrophobization ratios and side group sizes. Apparent water solubilities of pyrene, clofazimine, and AmB were increased up to 10 000, 20 000 and 1000 times, respectively, in aqueous solutions containing these polymers. The presence of sodium chloride in polymer solution increased pyrene solubility but decreased the solubilities of clofazimine and AmB, compared to the salt-free solutions. Synergy between hydrophobic and electrostatic interactions was observed for polar and cationic molecules. Degradation studies showed that the examined polymers were degradable, but none of them were totally degraded in 28 days. These polymers could be used as a new tool for drug solubilization.

Long-term human pluripotent stem cell self-renewal on synthetic polymer surfaces

Realization of the full potential of human pluripotent stem cells (hPSCs) in regenerative medicine requires the development of well-defined culture conditions for their long-term growth and directed differentiation. Current practices for maintaining hPSCs generally utilize empirically determined combinations of feeder cells and other animal-based products, which are expensive, difficult to isolate, subject to batch-to-batch variations, and unsuitable for cell-based therapies. Using a high-throughput screening approach, we identified several polymers that can support self-renewal of hPSCs. While most of these polymers provide support for only a short period of time, we identified a synthetic polymer poly(methyl vinyl ether-alt-maleic anhydride) (PMVE-alt-MA) that supported the long-term attachment, proliferation and self-renewal of HUES1, HUES9, and iPSCs. The hPSCs cultured on PMVE-alt-MA maintained their characteristic morphology, expressed high levels of markers of pluripotency, and retained a normal karyotype. Such cost-effective, polymer-based matrices that support long-term self-renewal and proliferation of hPSCs will not only help to accelerate the translational perspectives of hPSCs, but also provide a platform to elucidate the underlying molecular mechanisms that regulate stem cell proliferation and differentiation.

Preparation of thermally stable nanocrystalline hydroxyapatite by hydrothermal method

Thermally stable hydroxyapatite (HAp) was synthesized by hydrothermal method in the presence of malic acid. X-ray diffraction (XRD), Fourier transform infra-red spectroscopy (FT-IR), Raman spectroscopy, scanning electron microscopy (SEM), differential thermal analysis (DTA), thermogravimetric analysis (TGA) was done on the synthesized powders. These analyses confirmed the sample to be free from impurities and other phases of calcium phosphates, and were of rhombus morphology along with nanosized particles. IR and Raman analyses indicated the adsorption of malic acid on HAp. Thermal stability of the synthesized HAp was confirmed by DTA and TGA. The synthesized powders were thermally stable upto 1,400 degrees C and showed no phase change. The proposed method might be useful for producing thermally stable HAp which is a necessity for high temperature coating applications.

Les agents de régénération (ou RGTAs) : une nouvelle approche thérapeutique

RGTAs, or ReGeneraTing Agents constitute a new class of medicinal substance that enhance both speed and quality of tissue healing and leading in some case to a real tissue regenerating process. RGTAs consist of chemically engineered polymers adapted to interact with and protect against proteolytic degradation of cellular signaling proteins known as growth factors, cytokines, interleukins, colony stimulating factors, chemokines, neurotrophic factors etc. Indeed almost all these proteins of cellular communication are naturally stored in the extra cellular matrix interacting specifically with the heparan sulfates or HS. After tissue injury of any cause, cells die liberating glycanases and proteases inducing first HS degradation then liberation of the cytokines which in turn are susceptible to degradation as they are no longer protected. By replacing the natural HS, RGTAs will protect cytokines from proteolyses as they are liberated from the matrix compartment matter in the wound. This spatio-temporal selective protection of cytokines results in a preservation of the natural endogenous signaling of a tissue and is reflected by spectacular tissue regeneration or by a very greatly improved tissue repair. These observations indicate that mammals have an unexpected ability to regenerate and that RGTA helps to reveal this capacity. The aim of OTR3 is to develop RGTA into a drug to treat specific tissue lesions.

Improved Synthesis with High Yield and Increased Molecular Weight of Poly(α,β-malic acid) by Direct Polycondensation

The development of synthetic biodegradable polymers, such as poly(alpha-hydroxy acid), is particularly important for constructing medical devices, including scaffolds and sutures, and has attracted growing interest in the biomedical field. Here, we report a novel approach to preparing high molecular weight poly(malic acid) (HMW--PMA) as a biodegradable and bioabsorbable water-soluble polymer. We investigated in detail the reaction conditions for the simple direct polycondensation of l-malic acid, including the reaction times, temperatures, and catalysts. The molecular weight of synthesized alpha,beta-PMA is dependent on both the reaction temperature and time. The optimum reaction condition to obtain alpha,beta-PMA by direct polycondensation using tin(II) chloride as a catalyst was thus determined to be 110 degrees C for 45 h with a molecular weight of 5300. The method for alpha,beta-PMA synthesis established here will facilitate production of alpha,beta-PMA of various molecular weights, which may have a potential utility as biomaterials.