Liquid crystalline systems of glyceryl monooleate/water are used as drug delivery systems due to their complex structure that controls drug diffusion. Mucoadhesive properties of glyceryl monooleate suggest it can be used for buccal delivery. Using additives is a strategy to modify physical and chemical properties of liquid crystalline systems and optimize their performanceas a drug delivery system. However, the presence of additives can significantly alter properties such as phase behavior, swelling and mucoadhesion. Our aim is to investigate the influence of additives on swelling and mucoadhesion of glyceryl monooleate-based liquid crystals, intending them to be used as buccal drug delivery systems. The systems were characterized regarding their mesophases, swelling rate, and mucoadhesion. All the systems studied were able to absorb water and presented mucoadhesion, which is interesting for the development of buccal drug delivery systems. Additives induced phase transitions and affected the swelling performance, while mucoadhesive properties were poorly affected. Propylene glycol increased water uptake, while oleic acid induced the phase transition to the hexagonal phase and reduced the swelling rate. The association of oleic acid (5%) and propylene glycol (10%) resulted in a cubic phase system with strong mucoadhesive properties that can be a potential drug carrier for buccal delivery.

Third molar removal surgery usually comes accompanied by postoperative discomfort, which could be influenced by the surgical approach chosen. This scoping systematic review aimed at compiling the available evidence focused on the influence of flap design, including envelope flap (EF), triangular flap (TF), and modified triangular flap (MTF), on postoperative pain, swelling, and trismus, as primary outcome measures, and any result mentioning healing promotion or delay, as secondary outcome measure, after mandibular third molar extraction surgery. An electronic search, complemented by a manual search, of articles published from 1999 to 2020 was conducted in the Medline (PubMed), EMBASE and Web of Science databases including human randomized controlled trials, prospective, and retrospective studies with at least 15 patients. The risk of bias of the included studies was assessed either with the Cochrane’s Risk of Bias tool or with the Newcastle-Ottawa scale. Every step of the review was performed independently and in duplicate. The initial electronic search recovered 2102 articles. After applying the inclusion criteria, 12 articles were included. For patient’s perceived postoperative pain, TF and MTF frequently reported better results than EF. For swelling, the literature is divided, despite a trend favoring EF. For trismus, data showed that its occurrence is mostly associated with the duration of the surgery rather than with the chosen flap. For healing, the limited data is inconclusive. Finally, randomized studies showed a high risk of bias, whereas nonrandomized studies were mostly of good quality and low risk of bias. Although there was no clear consensus regarding the influence of different flap designs for third mandibular molar extraction on postoperative clinical morbidities; the surgeon’s experience, estimated surgical difficulty, molar position and orientation, and surg ery duration should be considered when choosing among the different flap designs.

Objective: Our study seeks to investigate the effectiveness of kinesio taping (KT) on postoperative morbidity compared to placebo and control groups after impacted third molar surgery. Methodology: Sixty patients with impacted mandibular third molar were included in this prospective, randomized, placebo-controlled clinical study. After surgical extraction of the impacted tooth, patients were allocated into three groups (20 patients each): group 1 received KT (kinesio), group 2 received placebo taping (placebo), and group 3 received no taping (control). The groups were compared regarding facial swelling, pain and trismus. Swelling was evaluated using a tape measuring method. Pain was assessed by a visual analog scale and the number of analgesic tablets taken. Trismus was determined by measuring maximum mouth opening. Results: In the KT group, all parameters reduced significantly on 2nd and 4th postoperative days compared to other groups; however, placebo and control groups revealed comparable outcomes. On 7th day, all groups showed comparable results. Conclusions: The KT application is an effective method for reducing morbidity after impacted mandibular third molar surgery. However, placebo taping is not as effective as proper taping. Placebo taping shows similar results compared to no taping regarding facial swelling percentage, pain and trismus.

Bleached acid sulphite and kraft Eucalyptus globulus pulps were subjected to treatment at high hydrostatic pressure (400 MPa during 10 min). The associated structural changes of cellulose were evaluated by X-ray scattering, solid-state NMR and infrared spectroscopy. The high pressure treatment promoted the growth of crystalline domains predominantly via lateral aggregation (cocrystallization) and, to some extent, due to the accretion of cellulose from noncrystalline domains (recrystallization). The treated pulps exhibited increment of the amount of strongly bound water and improved accessibility to amorphous domains. The high pressure treatment of dried sulphite pulp led to restoration, at least partially, of its swelling capacity thus diminishing the hornification features. Pressure treated dried sulphite pulp showed improved fibre bonding capacity at simultaneously increased bulk of the produced handsheets. The results obtained clearly showed the potential of high pressure treatments for the modification of cellulosic fibres in different applications.

Cationized fibers and other kinds of chemically modified fibers impart many advantages in papermaking, but unfeasibly long reaction times are necessary to attain acceptable degrees of substitution, due to the low reactivity of bleached kraft pulps. In this work, different aqueous pretreatments were tested in order to activate cellulose towards a 60 min-long etherification with a quaternary ammonium reagent. Severe decrystallization treatments, namely alkalization with NaOH 20%, NaOH/urea or FeTNa, conducted to the best reactivity results (substitution from 2 to 10%), but the fiber properties were harshly affected. Pretreatments involving H3PO4 at different concentrations were also performed, with distinct results, from unnoticeable effects at 20% to amorphization and excessive depolymerization at 80%. Finally, aqueous ammonium thiocyanate was tested as activator and had little effect on fibers, although the addition of ammonia resulted in high degrees of substitution, while maintaining the pulps’ capability to retain inter-fiber water and cellulose I as the prevalent allomorph.

lginate-based hydrogels can find uses in a wide range of applications, including in the encapsulation field. This type of hydrogels is usually ionically crosslinked using calcium sources giving rise to products with limited internal crosslinking. In this work, it is hypothesized that the combination of alginate crosslinked by calcium chloride (external crosslinking; ionic mechanism) with gelatin crosslinked by transglutaminase (internal crosslinking; enzymatic induced mechanism) can be used to tailor the swelling behavior of alginate-based hydrogel microspheres. A systematic study was conducted by covering process variables such as gelatin content, TGase concentration, and CaCl2 contact time, added by statistic tools as central composite rotatable design (CCRD), principal component analysis (PCA) and multiobjective optimization, to map their effect on the resulting water content after production (expressed as swelling ratio), and swelling properties at pH 3 and 7. Among the studied variables, particle's swelling was mostly affected by the gelatin content and transglutaminase concentration.

Changes in plasma membrane curvature and intracellular ionic strength are two key features of cell volume perturbations. In this hypothesis we present a model of the responsible molecular apparatus which is assembled of two molecular motors [non-muscle myosin II (NMMII) and protrusive actin polymerization], a spring [a complex between the plasma membrane (PM) and the submembrane actin-based cytoskeleton (smACSK) which behaves like a viscoelastic solid] and the associated signaling proteins. We hypothesize that this apparatus senses changes in both the plasma membrane curvature and the ionic strength and in turn activates signaling pathways responsible for regulatory volume increase (RVI) and regulatory volume decrease (RVD). During cell volume changes hydrostatic pressure (HP) changes drive alterations in the cell membrane curvature. HP difference has opposite directions in swelling versus shrinkage, thus allowing distinction between them. By analogy with actomyosin contractility that appears to sense stiffness of the extracellular matrix we propose that NMMII and actin polymerization can actively probe the transmembrane gradient in HP. Furthermore, NMMII and protein-protein interactions in the actin cortex are sensitive to ionic strength. Emerging data on direct binding to and regulating activities of transmembrane mechanosensors by NMMII and actin cortex provide routes for signal transduction from transmembrane mechanosensors to cell volume regulatory mechanisms.

The viscoelastic behaviour of chitosan was followed by dynamic mechanical analysis (DMA) while the sample was immersed in gradient compositions of water/ethanol mixtures. The swelling equilibrium of chitosan membranes, both crosslinked with genipin or not, increased linearly with the water content. Increasing the water content, it was simultaneously observed a peak in the loss factor (around 25 vol.%) and a reduction of the storage modulus, which was attributed to the a-relaxation of chitosan. This was the first time that the glass transition dynamics in a polymer was monitored in immersion conditions where the composition of the plasticizer in the bath is changed in a controlled way. The water content at which tan d presented a maximum increased with both increasing frequency and increasing crosslinking density. The permeability decreased steadily with the ethanol content, reaching very low values around the glass transition. Therefore we hypothesize that conformational mobility of the polymeric chains may play an important role in the diffusion properties of molecules trough polymeric matrices.

Studies of dynamic and equilibrium swelling, structural characterisation and solute transport in swollen poly(2-hydroxyethyl methacrylate) gels (pHEMA) cross-linked with tripropyleneglycol diacrylate (TPGDA) were done for a wide range of TPGDA concentrations. The influence of the pH on these pHEMA properties was evaluated. In swelling studies it was found that in changing the pH from 6.5 to 12.0, a large increase in swelling occurred, from approximately 48 to 55%, for the lowest concentration of TPGDA (1 mol%), and from 40 to 80% for the highest concentration (10mol%). Fourier transform infrared (FTIR) and differential scanning calorimetry (DSC) measurements were made after the equilibrium swelling of the gels at different pH values, to explain these results. The advantage of using these gels as controlled drug delivery systems is illustrated using salicylic acid (SA) as a model drug. The loading and the release of the SA were made at different pH values and the results obtained showed that it is possible to modulate the hydrogel performance by controlling an external factor, the pH at which the drug loading and release were performed.

Sugar-based hydrogels were prepared by non-selective modification of sucrose with the introduction of vinyl groups. Sucrose was reacted with glycidyl methacrylate (1:1 molar ratio) in DMSO and in the presence of 4-(N,N-dimethylamino)pyridine (4-DMAP) as catalyst. The structure of the product (SucMA) was established using 1H NMR, 1H DQF-COSY NMR and 13C NMR analysis. Gels were prepared by copolymerisation of hydroxyethyl methacrylate (HEMA) and SucMA in a 70:30 ethylene glycol/water mixed solvent using ammonium persulphate/sodium methabisulphite pair as initiating system. The swelling behaviour of these gels was evaluated as a function of crosslinker content, copolymer composition, pH and ionic strength. In addition, the diffusional behaviour of sodium salycilate (SSA) from these gels and poly(HEMA) gels is also reported.