Nanomaterial surface modification toolkit: Principles, components, recipes, and applications.

Surface-functionalized nanostructures are at the forefront of biotechnology, providing new opportunities for biosensors, drug delivery, therapy, and bioimaging applications. The modification of nanostructures significantly impacts the performance and success of various applications by enabling selective and precise targeting. This review elucidates widely practiced surface modification strategies, including click chemistry, cross-coupling, silanization, aldehyde linkers, active ester chemistry, maleimide chemistry, epoxy linkers, and other protein and DNA-based methodologies. We also delve into the application-focused landscape of the nano-bio interface, emphasizing four key domains: therapeutics, biosensing, environmental monitoring, and point-of-care technologies, by highlighting prominent studies. The insights presented herein pave the way for further innovations at the intersection of nanotechnology and biotechnology, providing a useful handbook for beginners and professionals. The review draws on various sources, including the latest research articles (2018-2023), to provide a comprehensive overview of the field.

Natural ß-chitin-protein complex film obtained from waste razor shells for transdermal capsaicin carrier.

In the literature, the produced ß-chitin samples are in powder or flake forms but there is no natural ß-chitin based film. Also, the commercially available transdermal patches are produced from synthetic polymers. In this regard, we produced natural ß-chitin-protein complex (CPC) film from the waste shells of Ensis spp. The obtained natural film was characterized by FTIR, TGA and SEM. Additionally, swelling, thickness, contact angle and antioxidant tests were done to learn more about the films. After production and characterization of the film, capsaicin, which is commonly used for pain relief was loaded into the film. The loading capacity was recorded as 5.79%. The kinetic models were studied in three different pH, then the results were fitted with Higuchi model with high correlation at pH 7.4. After considering all the obtained results, the capsaicin loaded CPC film may be an alternative candidate for transdermal patch instead of the synthetic ones.

Production of novel chia-mucilage nanocomposite films with starch nanocrystals; An inclusive biological and physicochemical perspective.

In the current study, chia mucilage composite films with starch nanocrystals (3% and 6%) were produced. The films were analyzed physicochemically (FT-IR, AFM, TGA, DSC), mechanically (Tensile strength and contact angle) and biologically (antimicrobial, antioxidant and cytotoxicity) properties. The incorporation of starch nanocrystals was confirmed through FT-IR spectra showing broad OH peak and CO stretching and shift in NH bending vibrations to the lower wave number. Starch nanocrystals enhanced (control 287.23 °C, film with 3% SNC 286.91 °C and film with 6% mucilage 289.41 °C) the thermal properties of the composite films. The Young Modulus of the film showed an increase after the incorporation of starch nanocrystals due to the strong interaction between mucilage and nanocrystals. On the other hand, the overall hydrophobicity of mucilage composite film decreased due to the hydrophilic nature of cornstarch nanocrystals. MTT assay for cell proliferation revealed significant inhibition of cancer cell (HepG2) lines and exhibits a very low inhibition of epithelial cell line (Vero). Starch nanocrystals enhanced the antibacterial and antioxidant (threefold increase compare to control) properties of mucilage composite films. Mucilage-SNC composite films could be a good therapeutic gain for control and directed drug delivery, food packaging, food coating.

Supplementing capsaicin with chitosan-based films enhanced the anti-quorum sensing, antimicrobial, antioxidant, transparency, elasticity and hydrophobicity.

In the current study, capsaicin, a plant alkaloid with high antioxidative, anti-inflammatory, antiobesity, anticancer and analgesic properties, was used in the film technology for the first time. In the same regard, chitosan (as a versatile animal-based polymer) was blended with capsaicin at three different concentrations to obtain edible films. The produced films were characterized by FT-IR, SEM, and DSC. Mechanical, transmittance, hydrophobicity, anti-quorum sensing, antimicrobial and antioxidant properties were also examined. Incorporation of 0.6 mg of capsaicin into the chitosan matrix (200 mg dissolved in 1% acetic acid solution) was observed as an optimal concentration for boosting up three film properties including mechanical, optical and surface morphology. A continuous improvement was recorded in anti-quorum sensing and antimicrobial activities, antioxidative and hydrophobicity with increasing concentration of capsaicin in the film. In further studies, chitosan-capsaicin blend films can be used as a food packaging material as well dermal and wound healing patches.

False flax (Camelina sativa) seed oil as suitable ingredient for the enhancement of physicochemical and biological properties of chitosan films.

To overcome the drawbacks of synthetic films in food packaging industry, researchers are turned to natural bio-based edible films enriched with various plant additives. In current study chitosan blend films were produced by incorporating Camelina sativa seed oil at varying concentrations to chitosan matrix. The chitosan blend films were characterized both physicochemically (structural, morphological, thermal, optical and mechanical) and biologically (antimicrobial and antioxidant activity). The incorporation of C. sativa seed oil notably enhanced thermal stability, antioxidative, anti-quorum sensing and antimicrobial activity. Except elongation at break, other mechanical properties of the blend films were not affected by incorporation of C. sativa seed oil. The surface morphology of blend films was recorded as slightly rough, non-porous and fibre-free surface. As it was expected the optical transmittance in visible region was gradually decreased with increasing fraction of seed oil. Interestingly the hydrophilicity of the blend films revealed a swift increase which can be explained by the formation of micelle between glycerol and Tween 40 in blend films. This study provides valuable information for C. sativa seed oil to be used as a blending ingredient in chitosan film technology.

Effect of different animal fat and plant oil additives on physicochemical, mechanical, antimicrobial and antioxidant properties of chitosan films.

Practical application of chitosan-essential oil blend films is limited due to the uneconomical extraction procedure of essential oils from plants. This study aimed to produce chitosan films blended with low cost and commercially available oils and fats consumed in daily human diet (olive, corn and sunflower oils, butter and animal fats). The study also focused on how physicochemical, biological and mechanical properties of chitosan blend films were influenced by the incorporation of oils and fats with varying unsaturation degrees. Possible interactions of chitosan film matrix with incorporated oils or fats were investigated. Chitosan-olive oil film showed better surface morphology and higher thermal stability than the films with other unsaturated oils. Tensile strength, Young's modulus and elongation at break were improved by 57.2%, 25.1% and 31.7% for chitosan-olive oil film, respectively. Chitosan-olive oil blend film had the highest antibacterial activity (almost equal to that of commercial antibiotic gentamicin). Edible films obtained from by incorporation of natural oils and fats into chitosan can help produce an environmentally friendly packaging material that is low cost and easily manufactured.

Diatomite as a novel composite ingredient for chitosan film with enhanced physicochemical properties.

Practical applications of biopolymers in different industries are gaining considerable increase day by day. But still, these biopolymers lack important properties in order to meet the industrial demands. In the same regard, in the current study, chitosan composite films are produced by incorporating diatomite soil at two different concentrations. In order to obtain a homogeneous film, glutaraldehyde was supplemented to chitosan solution as a cross-linker. Compositing diatomaceous earth to chitosan film resulted in improvement of various important physicochemical properties compared to control such as; enhanced film wettability, increase elongation at break and improved thermal stability (264-277°C). The microstructure of the film was observed to haveconsisted of homogeneously distributed blister-shaped structures arised due to the incorporation of diatomite. The incorporation of diatomite did not influence the overall antioxidant activity of the composite films, which can be ascribe to the difficulty radicals formation. Chitosan film incorporated with increasing fraction of diatomite revealed a notable enhancement in the antimicrobial activity. Additionally with the present study, for the first time possible interactions between chitosan/diatomite were determined via quantum chemical calculations. Current study will be helpful in giving a new biotechnological perspective to diatom in terms of its successful application in hydrophobic composite film production.

On chemistry of γ-chitin.

The biological material, chitin, is present in nature in three allomorphic forms: α, ß and γ. Whereas most studies have dealt with α- and ß-chitin, only few investigations have focused on γ-chitin, whose structural and physicochemical properties have not been well delineated. In this study, chitin obtained for the first time from the cocoon of the moth (Orgyia dubia) was subjected to extensive physicochemical analyses and examined, in parallel, with α-chitin from exoskeleton of a freshwater crab and ß-chitin from cuttlebone of the common cuttlefish. Our results, which are supported by13C CP-MAS NMR, XRD, FT-IR, Raman spectroscopy, TGA, DSC, SEM, AFM, chitinase digestive test and elemental analysis, verify the authenticity of γ-chitin. Further, quantum chemical calculations were conducted on all three allomorphic forms, and, together with our physicochemical analyses, demonstrate that γ-chitin is distinct, yet closer in structure to α-chitin than ß-chitin.

Controlled release and anti-proliferative effect of imatinib mesylate loaded sporopollenin microcapsules extracted from pollens of Betula pendula.

Sporopollenin is a promising material for drug encapsulation due to its excellent properties; uniformity in size, non-toxicity, chemically and thermally resilient nature. Herein, morphologically intact sporopollenin microcapsules were extracted from Betula pendula pollens. Cancer therapeutic agent (imatinib mesylate) was loaded into the microcapsules. The encapsulation efficiency by passive loading technique was found to be 21.46%. Release behaviour of the drug from microcapsules was found to be biphasic, with an initial fast release followed by a slower rate of release. Imatinib mesylate release from the drug itself (control) was faster than from imatinib mesylate-loaded sporopollenin microcapsules. The release profiles for both free and entrapped drug samples were significantly slower and more controlled in PBS buffer (pH 7.4) than in HCl (pH 1.2) buffer. Cumulative drug release from IM-MES-loaded sporopollenin microcapsules was found to be 65% within 24h for PBS, whereas release from the control was completed within 1h. Also, a complete dissolution of control in HCl buffer was observed within first 30min. MTT assay revealed that drug-loaded microcapsules were effective on WiDr human colon carcinoma cell line. B. pendula sporopollenin can be suggested as an effective carrier for oral delivery of imatinib mesylate.

Detailed adsorption mechanism of plasmid DNA by newly isolated cellulose from waste flower spikes of Thypa latifolia using quantum chemical calculations.

Current study was designed to use the newly obtained cellulose from waste flower spikes of Thypa latifolia plant for plasmid DNA adsorption. Cellulose was isolated according to a previously described method including acid and base treatment, and cellulose content was recorded as 17%. T. latifolia cellulose was physicochemically characterized via FT-IR, TGA and SEM techniques. Detailed mechanism of plasmid DNA adsorption by newly isolated cellulose was described using chemical quantum calculations. To check the effect of Cu++ immobilization on the affinity of cellulose for plasmid DNA, copper ions were immobilized onto T. latifolia cellulose. pUC18 plasmid DNA was used for adsorption studies. Membranes prepared with only T. latifolia cellulose and Cu++ immobilized T. latifolia cellulose revealed different adsorption ratios as 43.9 and 86.9% respectively. This newly isolated cellulose from waste flower spikes of T. latifolia can be utilized as a suitable carrier for plasmid DNA.

Newly isolated sporopollenin microcages from Platanus orientalis pollens as a vehicle for controlled drug delivery.

Sporopollenin microcages were produced from the pollens of Platanus orientalis. Paracetamol was loaded into the microcages. Pollen, sporopollenin, paracetamol and paracetamol-loaded sporopollenin microcages were characterized with FT-IR, TGA and SEM. The analytical analyses demonstrated that sporopollenin microcages were structurally intact, highly reticulated and thermally stable. The loading efficiency of the sporopollenin microcages was found to be 8.2% using the passive loading technique and 23.7% via evaporating loading technique. In vitro release and kinetics studies were performed to test the suitability of sporopollenin microcages for loading. These studies revealed that sporopollenin from P. orientalis can be suggested as a suitable carrier for drug loading and controlled release studies.

Encapsulation of Flurbiprofen by Chitosan Using a Spray-Drying Method with In Vitro Drug Releasing and Molecular Docking.

OBJECTIVES: This study aimed to prepare chitosan-flurbiprofen micro-nano spheres as environmentally friendly for drug releasing by spray-drying method without any cross-linking agent. It was also aimed to reveal the favorable binding geometries of chitosan and flurbiprofen using molecular modeling. MATERIALS AND METHODS: In this study, flurbiprofen was encapsulated with chitosan using spray-drying technique. The used chitosan, flurbiprofen and obtained spheres were characterized via fourier transmission infrared spectrometer (FT-IR), thermogravimetric analysis (TGA), X-ray diffractometer and scanning electron microscopy (SEM). Drug entrapment efficiency was carried out for determination of the drug amount in the micro-nano spheres. In vitro release studies of CS-FP spheres were also examined in the simulated biological fluid at pH 7.4. Encapsulation process of flurbiprofen was combined with the docking studies to investigate the possible binding sites of the chitosan. RESULTS: FT-IR results confirmed that H-bonding system was formed between chitosan and drug. CS-FP spheres with spherical shape were observed by SEM. TGA analysis results showed that thermal stabilities of flurbiprofen and chitosan were decreased after the encapsulation process. The spheres were used for in vitro releasing studies in simulated biological fluids. All these analysis results clearly showed that encapsulation was successfully carried out with 73.28% efficiency. Molecular modeling studies showed that CS-FP stable complexes was formed through a hydrogen bonding system between OH group of the drug molecule and chitosan hydroxyl (OH) group with a binding energy of -3.90 kcal/mol. Our computational results supported to spectroscopic results obtained by FTIR. CONCLUSION: This study proved that micro-nano spheres can be prepared without using cross-linking agent by spray-drying method. The results of the drug releasing studies showed that release of encapsulated flurbiprofen was completed within 48h. The results of docking analysis can be suggested for the design of new drug carrier systems with chitosan.

A new pollen-derived microcarrier for pantoprazole delivery.

Plant-derived carriers have emerged as promising materials for drug encapsulation. Especially, sporopollenin microcapsules extracted from diverse pollen species have been proved to be effective drug carriers due to their biocompatibility, homogeneity in size, resistance to harsh chemical conditions and high thermal stability. Here in this study, sporopollenin microcapsules were isolated successfully from the pollens of a common tree (Corylus avellana, the European hazelnut) and used as a carrier for pantoprazole (PaNa) (a proton pump inhibitor). The drug entrapment efficiency was recorded as 29.81%. SEM micrographs clearly showed the drug was loaded into the microcapsules through the apertures of microcapsule and also some drugs were adsorbed on the surface of microcapsules. FT-IR spectra analysis confirmed the drug loading. Thermogravimetric analysis revealed that thermal stability of PaNa was enhanced by encapsulation. In vitro release studies showed that PaNa-loaded sporopollenin microcapsules exhibited better release performance than the control. C. avellana sporopollenin microcapsules can make an efficient carrier for delivery of PaNa.

Conformation depends on 4D-QSAR analysis using EC-GA method: pharmacophore identification and bioactivity prediction of TIBOs as non-nucleoside reverse transcriptase inhibitors.

The electron conformational and genetic algorithm methods (EC-GA) were integrated for the identification of the pharmacophore group and predicting the anti HIV-1 activity of tetrahydroimidazo[4,5,1-jk][1,4]benzodiazepinone (TIBO) derivatives. To reveal the pharmacophore group, each conformation of all compounds was arranged by electron conformational matrices of congruity. Multiple comparisons of these matrices, within given tolerances for high active and low active TIBO derivatives, allow the identification of the pharmacophore group that refers to the electron conformational submatrix of activity. The effects of conformations, internal and external validation were investigated by four different models based on an ensemble of conformers and a single conformer, both with and without a test set. Model 1 using an ensemble of conformers for the training (39 compounds) and test sets (13 compounds), obtained by the optimum seven parameters, gave satisfactory results (R²(training) = 0.878, R²(test)= 0.910, q² = 0.840, q²(ext1) = 0.926 and q²(ext2) = 0.900).