In this research, the use of coconut fibers in the development of medical wound dressing sheets was investigated. The fiber preparation process involved cleaning the fibers with distilled water, boiling for 1 h, and soaking in a 10 g/L NaOH solution for 4 h. The fibers were then bleached in a 30% hydrogen peroxide (H2O2) solution for 3 h after the alkaline treatment. The fibers were formed into sheets using a mesh mold to create a smooth molded surface. The surface morphology was analyzed and tested using a scanning electron microscope (SEM) and the chemical structure was characterized with Fourier transform infrared (FTIR) spectroscopy. Biodegradation was evaluated by measuring water adsorption at different stages of drying. The results of the SEM analysis of the coconut fibers revealed a thin elongated shape and depositions forming overlapping structures that resembled a shiny film. The absorption peak of lignin at 1730 cm-1 in the FTIR spectrum decreased in the 1244-1730 cm-1 range after alkaline treatment. Functional groups corresponding to lignin, hemicellulose, and fat were found to be removed well by the combined bleaching and NaOH treatment. The tests indicate that the molded fiber sheets biodegrade under soil burial with simulated natural conditions, with an average biodegradation temperature of 33.1 degrees C-35.4 degrees C, at a significance level of 0.05. These results suggest that physically and chemically treated coconut fibers are promising biodegradable materials for medical wound dressings, offering environmentally friendly alternatives to synthetic wound dressings.

Chronic wounds require bioactive dressings that protect the wound site while promoting a suitable healing environment, regulating oxidative stress, and enabling sustained delivery of therapeutic agents. Although electrospun polylactic acid (PLA) fibers are attractive for wound dressing applications because of their biodegradability and extracellular matrix-mimicking structure, their intrinsic hydrophobicity limits bioactivity and fluid management. In this study, rutin-loaded cellulose nanocrystals (CNCs)/PLA/Pluronic P123 composite nanofibers were developed via electrospinning to enhance hydrophilicity and achieve sustained antioxidant release. The incorporation of CNCs and P123 significantly improved the wettability of PLA fibers, transforming the originally hydrophobic fibrous surface into a hydrophilic platform. Rutin incorporation partially restored the tensile performance of the composite fibers by improving both tensile strength and elongation at break. The fibers exhibited biphasic rutin release, with an initial burst release up to 25% within 1 h, followed by sustained release up to 65% over 48 h. Release kinetics were predominantly governed by diffusion-controlled behavior according to the Korsmeyer-Peppas model. Furthermore, the fibers retained strong antioxidant activity, showing nearly 90% DPPH radical-scavenging activity, and demonstrated non-cytotoxicity toward human dermal fibroblasts. These findings suggest that the developed RUT-CNCs/PLA/P123 fibers are promising bioactive wound dressing materials with improved hydrophilicity, sustained release capability, antioxidant activity, and cytocompatibility.

Chronic wound treatment presents a significant challenge, requiring bioactive scaffolds that facilitate effective wound repair and promote skin regeneration with normal functionality. In this study, gellan gum (GG) networks were formed via physical crosslinking with divalent cations, while silk sericin (SS), as the linear phase, molecularly penetrated the pore volume of the GG network, resulting in the formation of semi-interpenetrating polymeric networks (semi-IPNs). The GG/SS scaffolds were enriched with betel leaf extract-encapsulated β-cyclodextrin complexes (B-ICs) to preserve the bioactive substance, improve the controlled release, and provide antibacterial, antioxidant and anti-inflammatory properties. Characterization through XRD, FTIR, and thermal analyses confirmed successful encapsulation and enhanced thermal stability, while SEM imaging revealed well-formed microporous structures. Mechanical testing showed that B-ICs significantly improved the compressive modulus and strength of the scaffolds. Additionally, the controlled release behavior of the B-ICs-GG/SS scaffolds, confirmed by the Korsmeyer-Peppas model, suggested anomalous transport as the release mechanism, aligning with the faster in vitro degradation rate. The scaffolds exhibited high phenolic content, resulting in excellent free radical scavenging activity to minimize oxidative stress and support an optimal wound healing environment. In vivo skin irritation test in rabbits confirmed that B-ICs-GG/SS scaffolds were non-irritant, suggesting the dermal safety and biocompatibility of the materials, a critical requirement for clinical translation. As a result, the B-ICs-GG/SS scaffolds would be a promising candidate for wound healing and tissue engineering applications.

Controlled release fertilizers (CRFs) promote sustainable agriculture by gradually releasing nutrients into the soil while also mitigating environmental pollution. Nitrogen-phosphorus-potassium embedded hydroxyapatite/alginate (NPK-HA/Alg) biocomposite beads were developed using a simple, cost-effective, and environmentally friendly dropping and external gelation method. Addition of eggshell biowaste-derived HA to the alginate matrix improved the structural, thermal, and structural stability of the alginate beads, and enabled the inclusion of significantly high plant nutrients. The biocomposite beads exhibited a prolonged and controlled nutrient release in deionized water over 35 days. Biocomposite bead addition was assessed for the growth of flowering Chinese cabbage in a controlled greenhouse environment. Results confirmed vegetative growth with high values of plant height, number of leaves, and fresh and dry weights. The non-toxic and cost-effective NPK-HA/Alg biocomposite beads demonstrated controlled nutrient release as promising CRF materials to promote sustainable agricultural production.

Bacterial infection and inflammation caused by excess oxidative stress are serious challenges in chronic wound healing. The aim of this work is to investigate a wound dressing based on natural- and biowaste-derived biopolymers loaded with an herb extract that demonstrates antibacterial, antioxidant, and anti-inflammatory activities without using additional synthetic drugs. Turmeric extract-loaded carboxymethyl cellulose/silk sericin dressings were produced by esterification crosslinking with citric acid followed by freeze-drying to achieve an interconnected porous structure, sufficient mechanical properties, and hydrogel formation in situ in contact with an aqueous solution. The dressings exhibited inhibitory effects on the growth of bacterial strains that were related to the controlled release of the turmeric extract. The dressings provided antioxidant activity as a result of the radical scavenging effect on DPPH, ABTS, and FRAP radicals. To confirm their anti-inflammatory effects, the inhibition of nitric oxide production in activated RAW 264.7 macrophages was investigated. The findings suggested that the dressings could be a potential candidate for wound healing.

Active dressings demonstrating biological activities, such as antibacterial, antioxidant, and anti-inflammatory activities, play an essential role in chronic wound healing. Carboxymethyl cellulose/ silk sericin (CMC/SS) scaffolds incorporated with turmeric (T) herb extracts and cross-linked with nontoxic citric acid were prepared by freeze-drying and used for the controlled release of turmeric. The chemical and physical properties of the fabricated T-CMC/SS scaffolds were investigated, and their biological functions necessary for wound healing applications were elucidated. The T-CMC/SS scaffolds showed uniform and highly interconnected porous structures. The SS in the CMC scaffolds significantly enhanced the mechanical properties and thermal stability of the scaffolds, which can overcome the insufficient mechanical strength and thermal instability of biopolymers. The T-CMC/SS scaffolds exhibited inhibitory effects on the growth of bacterial strains Staphylococcus aureus and Escherichia coli , which is related to the controlled release behavior of turmeric. The scaffolds loaded with turmeric had excellent antioxidant activity according to the 2,2-diphenyl-1-picrylhydrazyl assay results. High cell viability (>80%) indicated that the scaffolds were noncytotoxic and the used materials were biocompatible. The anti-inflammatory activities of turmeric-loaded scaffolds were demonstrated by the inhibition of nitric oxide production in activated RAW 264.7 macrophages. The T-CMC/SS scaffolds are thus promising active wound dressings with the great mechanical and thermal stability and biological properties required for wound healing applications.

A spray-on wound dressing has many benefits, including easy and quick administration to broad and uneven wounds, better interface with the wound site, adhesion without additional dressing, and multiple applications in a portable package. By limiting direct contact with the wound site, such a design can prevent wound damage during treatment. This study revealed a simple, one-pot synthesis of spray-on wound dressing relying on polyvinylpyrrolidone solution incorporating silver nanoparticles as a broad-spectrum antibacterial agent and wound-healing antioxidant Phyllanthus emblica extract. Silver nanoparticles were synthesized in situ using Phyllanthus emblica extract as a biogenic reducing agent. Polyvinylpyrrolidone was employed as a film-forming agent to create an adhesive hydrogel-based dressing matrix to provide moisture and establish a shielding barrier for the wound bed as well as to regulate the release of fruit extract. In vitro tests revealed that the produced dressing film had a controlled release of the fruit extract, high antioxidant activity, and a good antibacterial action against S. aureus, P. aeruginosa, E. coli, and MRSA. Additionally, a biocompatibility study has shown that both human fibroblasts and keratinocytes are unaffected by the dressing film. Based on established findings, the current spray-on solution might be a potential option for antibacterial wound dressing.

The novel and facile preparation of magnetically interconnected micro/ macroporous structure of monolithic porous carbon adsorbent (MPCA) were designed and presented herein. The synthesis was achieved via conventional freeze-drying and pyrolysis processes. In this study, sodium alginate and wasted black liquor were employed as starting precursors. Sodium alginate acts as a template of materials, whereas black liquor, the wasted product from the paper industry with plentiful of lignin content and alkaline solution, played an essential role in the reinforcement and activation of porosity for the resulting materials. Moreover, both the precursors were well dissolved in Fe3+ solution, providing a simple addition of a magnetic source in a one-pot synthesis. The interconnected micro/macroporous structures were generated through freeze-drying and, subsequently the pyrolysis process. The obtained cylindrical-shaped monolithic porous carbon adsorbent (MPCA-700) showed high mechanical stability, a high BET specific surface area (902 m2 /g). Such aforementioned features were considered suitable to make the synthesized monolith as an adsorbent for the removal of heavy metal ions. The maximum adsorption capacity of MPCA-700 towards Pb2+ ions was 76.34 mg/g at pH 5. The adsorption studies illustrated that adsorption kinetics and isotherm perfectly fitted with the pseudo-second-order kinetics model and Langmuir isotherm, respectively. This work presents a promising protocol to reduce the overall costs in the preparation of renewable adsorbents with good adsorption efficiency and regeneration.

Tissue engineering is a promising approach to repair and regenerate damaged or lost tissues or organs. In dental aspect, reconstruction of the resorbed alveolar bone after tooth extraction plays an important role in the success of dental substitution, especially in dental implant treatment. The hydroxyapatite (HA)-incorporated fibroin-alginate composite injectable hydrogel was fabricated to be used as scaffold for bone regeneration. HA was synthesized from eggshell biowaste. Fibroin was extracted from Bombyx mori cocoon. The synthesized HA, fibroin and alginate hydrogel were characterized. HA-incorporated fibroin-alginate hydrogel had decreased pore size and porosity compared with pure alginate hydrogel. Thermal analysis showed that hydrogel had a degradation peak of approximately 250 °C. Hydrogel could absorb water, with a swelling ratio of around 300% at 24 h. Hydrogel was degraded as time passed and almost completely degraded at day 7. Its compressive Young's modulus was approximately 0.04 ± 0.02 N/mm2 to 0.10 ± 0.02 N/mm2. Primary cytotoxicity test indicated non-toxic potential of the fabricated hydrogel. Increased ALP activity was observed in MC3T3-E1 cultured in HA-incorporated fibroin-alginate hydrogel. Results suggested the potential use of injectable HA fibroin-alginate hydrogel as dental scaffolding material. Further studies including in vivo examinations are needed prior to its clinical application.

Suitable three-dimensional scaffolds showing controllable drug delivery properties, known as multifunctional scaffolds, have gained increasing interest for soft tissue engineering. Here, tetracycline hydrochloride-encapsulated polylactic acid (TCH-PLA) microparticles prepared by using the double emulsion/solvent evaporation method were incorporated into a gelatin matrix. Highly interconnected porous TCH-PLA-in-Gel scaffolds were formed by using lyophilization. In vitro release studies showed that the scaffolds exhibit a controlled release behavior and release low amounts of the drug. TCH-PLA particles additionally reinforced porous gelatin scaffolds and enhanced thermal stability. Antibacterial activity of the scaffolds against Staphylococcus aureus and Escherichia coli was confirmed by using the disk diffusion method. The scaffolds exhibited biocompatibility with adult human dermal fibroblasts, without cytotoxicity. Results indicated that TCH-PLA-in-Gel scaffolds showing multifunctional properties are good candidates for the applications of soft tissue engineering.

A controlled release system of Plai (Zingiber cassumunar Roxb.) oil based on electrospun poly(lactic) acid (PLA) nanofiber mat was successfully developed. The physicochemical properties of the nanofibers loaded with select amounts of oil (15%, 20%, and 30% wt) were characterized using various techniques, including a morphological study using scanning electron microscopy (SEM), structural determination using Fourier transform infrared spectrometry (FTIR) and x-ray diffraction (XRD), as well as thermal properties study using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The loading content and the entrapment efficiency of Plai oil within the fiber mats were evaluated and were found to be remarkably high, ensuring that PLA was an appropriate material for Plai oil loading. The ability of the nanofiber mats to release (E)-1-(3,4-dimethoxyphenyl) butadiene (DMPBD) was also examined and the fiber mats showed controlled release characteristics. As the nanofiber mats have particularly high specific surface area with fully accessible and interconnected pore structures, a liquid medium with active ingredients will not be trapped in blind pores but can be fully released out of the fiber matrix. Furthermore, in vitro skin permeation of the active compound as well as a skin irritation were assessed using reconstructed human epidermis (EpiSkinTM). It was found that DMPBD could efficiently penetrate through the skin model. Moreover, the nanofiber mats containing Plai oil also showed no skin irritation, indicating them as promising prototypes for medical applications.

Using controlled-release fertilizers (CRFs) is one of the sustainable strategies that improve the effectiveness of fertilizers in agricultural production. In the present study, CRFs were developed by encapsulating nitrogen–phosphorus–potassium (NPK) nutrients with core/shell fibers. The NPK-loaded core/shell fibers were fabricated using co-axial electrospinning based on biodegradable and biocompatible hydrophilic and hydrophobic polymers, including polyvinyl alcohol (PVA) as the core phase and polylactic acid (PLA) as the shell phase. The influences of core/shell structures and polymers used on the physical properties, release profile, degradation behavior, and function of the fertilizer in the field were investigated. Results showed that the PVA/PLA core/shell fibers with diameters in micro-sizes provided higher encapsulation efficiency compared with the PVA monolithic fibers. The core/shell fibers enhanced the stability and release characteristics of the plant nutrients in a controlled manner. Plant growth assessment undertaken with green cos lettuce and red cos lettuce showed that the tested fertilizers were not toxic to the plants. Only one application at the beginning of planting showed simulating effect on vegetative growth parameter and effectively promoted good quality of plant growth. As the results, the NPK-loaded PVA (core)/PLA (shell) fibers could act as CRFs with showing controlled release of fertilizers which are suitable for sustainable agriculture.

Tissue engineering involves a multifunctional temporary matrix which regulates tissue regeneration through controlled drug release against infections. A nanofibrous core-sheath structured scaffold comprising a tetracycline-loaded alginate/soy protein isolate (TCH-Alg/SPI) as a core and polycaprolactone (PCL) as a sheath was developed using co-axial electrospinning. Coverage of hydrophobic PCL on TCH-Alg/SPI fibers enhanced their structural stability in aqueous solutions as unsheathed fibers rapidly decomposed and provided fast drug release. Core-sheath fibers exhibited an initial burst release at ~49 % after 6 h of immersion in phosphate-buffered saline (PBS) solution and the sustain release reached ~80 % of total loaded drug on day 14. Release characteristics of TCH-Alg/SPI fibers without PCL covering showed immediate drug release within 48 h. Core-sheath fibers investigated by disk diffusion exhibited antibacterial properties against Staphylococcus aureus and Escherichia coli. The non-toxicity of core-sheath fibers was confirmed by an indirect cytotoxicity test using human dermal fibroblasts which showed compatibility and high cell viability of up to 100 % in treated cells. TCH-Alg/SPI-PCL core-sheath fibers show promise as tissue engineering scaffolds which can act as temporary templates for tissue regeneration and exhibit antibiotic release functions against infections caused by pathogenic microorganisms.

In a large number of medical devices, a key feature of a biomaterial is the ability to successfully bond to living tissues by means of engineered mechanisms such as the enhancement of biomineralization on a bone tissue engineering scaffold or the mimicking of the natural structure of the extracellular matrix (ECM). This ability is commonly referred to as "bioactivity". Materials sciences started to grow interest in it since the development of bioactive glasses by Larry Hench five decades ago. As the main goal in applications of biomedical devices and tissue scaffolds is to obtain a seamless tissue-material interface, achieving optimal bioactivity is essential for the success of most biomaterial-based tissue replacement and regenerative approaches. Polymers derived from lactic acid are largely adopted in the biomedical field, they are versatile, FDA approved and relatively cost-effective. However, as for many other widespread biomedical polymers, they are hydrophobic and lack the intrinsic ability of positively interacting with surrounding tissues. In the last decades scientists have studied many solutions to exploit the positive characteristics of polylactide-based materials overcoming this bottleneck at the same time. The efforts of this research fruitfully produced many effective tissue engineering technologies based on PLA and related biopolymers. This review aims to give an overview on the latest and most promising strategies to improve the bioactivity of lactic acid-based materials, especially focusing on biomolecule-free bulk approaches such as blending, copolymerization or composite fabrication. Avenues for future research to tackle current needs in the field are identified and discussed.

Three-dimensional (3D) porous alginate/soy protein isolated (Alg/SPI) tissue engineering scaffolds were achieved by freeze-drying. The physico-chemical attributes of the scaffolds including morphology, chemical structure, mechanical properties and in vitro cytotoxicity were investigated for different SPI blends. Results indicated that increasing SPI content to 40 wt% in the blends resulted in the partial existence of closed pores and reduced pore size. The mechanical values of the scaffolds under compression also reduced with increasing SPI in the blends. The addition of SPI did not significantly enhance the cell viability of the scaffolds investigated for in vitro culture with human fibroblasts, which remained in the high (90 – 100%) range. Results demonstrated that Alg/SPI scaffolds have potential for use as tissue engineering scaffolds.

This study aimed to fabricate electrospun poly(lactic acid) (PLA) fiber mats containing 3 kinds of rice extract (rice bran, riceberry and LeumPhum rice extracts) by using electrospinning. The rice extract has been reported to exhibit antioxidant activities. The neat and rice extract-loaded PLA fiber mats were smooth and no beads formed on the fiber surface with diameters ranging from 450-656 nm. Release characteristics of the rice extract-loaded electrospun PLA fiber mats were investigated using total immersion methods. The scavenging ability of LeumPhum rice extract-loaded electrospun fibers showed superior scavenging activity as determined using the DPPH radical scavenging method. The results suggested that rice extract incorporated in PLA nanofibers had no negative effect on antioxidant activity when using an electrospinning process.

Natural polymer-based nanofibers with functions of loading and releasing bioactive cues or drugs have recently gained interest for biomedical applications. Nanotopography and large surface area to volume ratio of hydrophilic polymer fibers promote their use as carriers of hydrophilic drugs. Here, sodium alginate (SA) and soy protein isolated (SPI) blended fibers encapsulated with vancomycin were fabricated via electrospinning with the assistance of poly(ethylene oxide) (PEO). Morphological results showed submicron-sized, smooth and uniform as-spun SA/PEO/SPI fibers with an average diameter of 200 nm. Beads on the fiber mats were formed with increasing SPI content in the blending system. The optimal polymer composition of the electrospinning solution was determined as 5.6/2.4/2 SA/PEO/SPI. Polymer blends were maintained after ionic “cross-linking”, as indicated by the FTIR result. Investigation of release characteristic of vancomycin-loaded SA/PEO/SPI electrospun fibers exhibited initial burst release followed by a controlled release after 2 days of immersion in a phosphate buffered saline. The release rate of SA/PEO/SPI fibers was significantly slower than that of SA/PEO fibers, and drug-loaded fibers inhibited bacterial growth against Staphylococcus aureus after 24 h of incubation. Non-toxicity and biocompatibility of the fibers were confirmed by an indirect cytotoxicity test using human dermal fibroblasts. These results suggest that the vancomycin-loaded SA/PEO/SPI blended fibers are a promising nanomaterial for use in biomedical fields such as scaffolds for tissue engineering and drug delivery systems.

Green polymer-based hydrogels have been broadly applied in the pharmaceutical, medical, food and agricultural industries. Alginate/gelatine blended hydrogels loaded with guava leaf extract were prepared using the simple physical crosslinking in situ gelation method. Different blending ratios were investigated in terms of the physico-chemical properties of the hydrogels including morphology, chemical composition, mechanical properties, water absorption and release behaviour. Results indicated that gelatine content had a positive effect on loading capacity and encapsulation efficiency. Increasing gelatine content in the blends significantly improved tensile properties, particularly elongation at fracture, while the ability of the hydrogels to absorb water decreased with increasing gelatine quantity. Extract-loaded hydrogels expressed high antioxidant activity, reaching approximately 70% 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging after 30 min immersion in saline solution. Extract release from the hydrogels was controlled by swelling and polymer relaxation mechanisms according to the Korsmeyer–Peppas kinetic model. Results suggested that antioxidant-loaded alginate/gelatine hydrogels are of interest for biomedical applications.

To overcome the limited intrinsic cartilage repair, autologous chondrocyte or bone-marrow-derived mesenchymal stromal cell (BM-MSC) was implanted into cartilage defects. For this purpose suitable biocompatible scaffolds are needed to provide cell retention, chondrogenesis and initial mechanical stability. The present study should indicate whether a recently developed highly porous alginate (Alg) foam scaffold supplemented with chondroitin sulfate (CS) allows the attachment, survival and chondrogenesis of BM-MSCs and articular chondrocytes. The foams were prepared using a freeze-drying method; some of them were supplemented with CS and subsequently characterized for porosity, biodegradation and mechanical profile. BM-MSCs were cultured for 1–2weeks on the scaffold either under chondrogenic or maintenance conditions. Cell vitality assays, histology, glycosaminoglycan (sGAG) assay, and type II and I collagen immunolabelings were performed to monitor cell growth and extracellular matrix (ECM) synthesis in the scaffolds. Scaffolds had a high porosity ~93–95% with a mean pore sizes of 237±48μm (Alg) and 197±61μm (Alg/CS). Incorporation of CS increased mechanical strength of the foams providing gradually CS release over 7days. Most of the cells survived in the scaffolds. BM-MSCs and articular chondrocytes formed rounded clusters within the scaffold pores. The BM-MSCs, irrespective of whether cultured under non/chondrogenic conditions and chondrocytes produced an ECM containing sGAGs, and types II and I collagen. Total collagen and sGAG contents were higher in differentiated BM-MSC cultures supplemented with CS than in CS-free foams after 14days. The cell cluster formation induced by the scaffolds might stimulate chondrogenesis via initial intense cell–cell contacts.

This article presents data related to the research article entitled “The effect of coating type on mechanical properties and controlled drug release of PCL/zein coated 45S5 bioactive glass scaffolds for bone tissue engineering” [1]. We provide data on mechanical properties, in vitro bioactivity and drug release of bioactive glass (BG) scaffolds coated by poly (ε-caprolactone) (PCL) and zein used as a controlled release device for tetracycline hydrochloride (TCH). By coating the BG scaffolds with PCL or PCL/zein blend the mechanical properties of the scaffolds were substantially improved, i.e., the compressive strength increased from 0.004±0.001MPa (uncoated BG scaffolds) to 0.15±0.02MPa (PCL/zein coated BG scaffolds). A dense bone-like apatite layer formed on the surface of PCL/zein coated scaffolds immersed for 14 days in simulated body fluid (SBF). The data describe control of drug release and in vitro degradation behavior of coating by engineering the concentration of zein. Thus, the developed scaffolds exhibit attractive properties for application in bone tissue engineering research.