Preparation and application of curcumin loaded with citric acid crosslinked chitosan-gelatin hydrogels

While oral administration offers safety benefits, its therapeutic efficacy is hindered by various physiological factors within the body. In this study, a novel approach was explored using a matrix consisting of 2 % chitosan and 2 % gelatin, with citric acid (CA) serving as a green cross-linking agent (ranging from 0.4 % to 1.0 %), and curcumin (Cur) as the model drug to formulate hydrogel carriers. The results showed that a 0.4 % CA concentration, the hydrogel (CGA0.4) reached swelling equilibrium in deionized water within 40 min, exhibiting a maximum swelling index was 539 g/g. The addition of Cur to the CGA hydrogel (CGACur) notably enhanced release efficiency, particularly in simulated intestinal fluid, where Cur release rates exceeded 40 % within 100 min compared to below 8 % in other solutions. Among these hydrogels, CGA0.4Cur exhibited the fastest degradation rate in the combined solution, reaching >90 % degradation after 7 days. Additionally, Cur and CA demonstrated positive effects on the tensile strength, antioxidant activity and antibacterial activity of hydrogels. Compare to the bioaccessibility of CGC (27 %), those of CGACur had increased to over 34 %. These findings offer provide theoretical support for CA-crosslinked chitosan/gelatin gels in delivering hydrophobic bioactive molecules and their application in intestinal drug delivery system.

Preparation, physicochemical and application evaluation of raspberry anthocyanin and curcumin based on chitosan/starch/gelatin film

Raspberry anthocyanin (RA) from Rubus idaeus L. (Rosaceae) and curcumin (Cur) from Curcuma longa L. (Zingiberaceae) can effectively improve the physicochemical properties of composite films, and as bioactive pigment components, they can impart pH-responsive properties to the film. In this study, RA and Cur were added to chitosan/starch/gelatin composite film (CSG) to prepare CSG-RA, CSG-Cur, CSG-RA/Cur₈₂ and CSG-RA/Cur₇₃ color films by solution casting method. The color films could change color under different pH conditions and had higher antioxidant activities using ABTS (2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid)) assay. The results from fourier transform infrared spectroscopy and scanning electron microscopy showed that RA and Cur were well dispersed in the CSG matrix and improved the structure of the composite films. The hydrophobic Cur increased the tensile strength from 6 Mpa (CSG) to 14 Mpa (CSG-Cur), but reduced the elongation at break from 55 % (CSG) to 40 % (CSG-Cur). These color films had a good fresh-keeping effect and freshness monitoring, in particular, CSG-RA/Cur₇₃, had the better opacity, water solubility, thickness, moisture content and water vapor permeability than the other films. Briefly, binary pigment films had the potential to become a pH-sensitive indicator/packing film.

Pectin/sodium alginate/xanthan gum edible composite films as the fresh-cut package

Due to the convenience, fresh-cut vegetables or fruits as the emerging commercial products have attracted much attention in recent years. However, the preservation of food with high quality remains a big challenge. In this study, one novel kind of edible composite film (PAX) consisted of pectin, sodium alginate (SA), and xanthan gum (XG) was well developed. The optimum concentrations for pectin and SA in PAX film based on the shearing viscosity were 6 g/L and 5 g/L, respectively. Upon this condition, the experimental results from the response surface methodology showed that the tensile strength for the optimized PAX (PAX_O) film can reach the maximum value of 29.65 MPa at the concentration of 4 g/L XG, 18 g/L glycerol, and 20 g/L CaCl₂. The corresponding elongation at break was 19.02% and the water vapor transmission rate was evaluated to be 18.12 × 10^-11 g/(m²·s·pa). Furthermore, the nanocomposites in terms of coating or films were used to keep fresh-cut potatoes, where they exhibited different efficiencies in food preservation with the order: PAX_O coating + CaCl₂ ≈ PAX_O coating > PAX_O film > sterile water. All the results indicated that the as-prepared PAX_O film or PAX_O solution could be good candidates in packaging preservation.

Intracranial aneurysms: experience in treating 500 patients

OBJECTIVE

To summarize the experience in surgical treatment of patients with intracranial aneurysms.

METHODS

The measures used in the treatment of 500 patients with intracranial aneurysms were retrospectively reviewed with regard to timing of surgery, induced-hypotensive anesthesia, brain protection combined with temporal occlusion of the feeding artery, dynamically monitoring of transcranial Doppler ultrasound, antivasospasm treatment, techniques of direct surgery, and endovascular embolization.

RESULTS

In 465 patients undergoing surgery, intraoperative rupture was observed in 27(6.2%), postoperative death in 13 (2.7%), hemipalsy in 8(2.2%), and vegetative state in 2 (5.0%). The operative mortality was 3.8% in 210 patients before 1990, while 1.9% in 255 patients after 1990.

CONCLUSION

The outcome of patients with intracranial aneurysms can be markedly improved by comprehensive measures.

[Clinico-transcranial Doppler sonography monitoring on vasospasm and delayed cerebral ischemia after resection of intracranial tumors]

The occurrence of vasospasm and delayed cerebral ischemia after resection of intracranial tumor has not received extensive attention clinically, and is often misdiagnosed and improperly treated as surgical brain damage or brain swelling. Seventy-two patients with intracranial tumor were continuously monitored pre- and postoperatively by means of neurological assessment and transcranial Doppler sonography. Vasospasm was found in 35 (48.6%) patients (18 mild, 13 moderate and 4 severe vasospasm). No significant difference among age, sex, surgical approaches, pathological diagnosis, duration of surgery, amount of blood loss and transfusion during surgery were found, but significant difference was seen in cisternal hemorrhage on CT scan and the amount of blood in cerebrospinal fluid. The cause and features of postoperative vasospasm were discussed, transcranial Doppler sonography played an important role in the diagnosis of vasospasm. To decrease the amount of blood in basal cistern by microsurgery in preventing vasospasm and to differentiate vasospasm from brain swelling are helpful to confirm the coexistent or causal relation based on neurological assessment, CT imagine, transcranial Doppler sonography and ICP monitoring both in deciding therapeutic strategy and successfully controlling vasospasm. Nimotop played a key role in preventing brain damage from vasospasm and cerebral swelling.

[Comprehensive treatment of intracranial aneurysm complicated by postoperative vasospasm]

Forty six patients suffered from intracranial aneurysm complicated by postoperative vasospasm and delayed cerebral ischemia were monitored dynamically both by clinical observation of neurologic status and multiple items such as transcranial Doppler, serum osmolality, intracranial pressure and other somatic physiologic items related to monitoring. Patients were intensively and comprehensively treated according to individualized grading of vasospasm. Forty four patients (95.6%) were completely recovered from postoperative vasospasm and delayed cerebral ischemia, while 2 patients (4.3%) complicated by hemipalsy as a consequence of delayed cerebral ischemia. The occurrence of vasospasm and delayed cerebral ischemia, the criteria of TCD grading, the valuableness of multiple physiologic items and problems related to comprehensive treatment are discussed.

[The role of serum osmolality monitoring in patients with severe intracranial lesion]

We dynamically determined serum osmolality in 1379 patients with severe intracranial lesion for 2843 times between January 1992 and July 1995. Using auto-control and after abandoned osmolality related interference factors we obtained the following results. Quantitative correlation analysis on the level of serum osmolality, intracranial pressure and the dose of mannitol showed that there was a negative correlation between the level of serum osmolality and intracranial pressure, while a positive correlation existed between the intracranial pressure and the dose of mannitol. The reasonable dose of mannitol was that which elevated the level of serum osmolality some 15-20 mOsm/kgH2O than its normal upper limit. The level of serum osmolality increesed to raised up 20-30 mOsm/kgH2O after administration of a single dose of mannitol. Complication increased with the increased level of osmolality of 300 mOsm/kgH2O, a warning level. An elevation of osmolality over 320 mOsm/kgH2O was considered the critical level for developing acute renal failure. The level of over 330 mOsm/kg H2O was another warning level for inducing nonketotic hyperosmotic diabetic coma. The efficious duration of mannitol, two different ways of diminishing or withdrawing the dose of mannitol, and the more safer velocity for correcting the state of hyperosmolality were also discussed. We conclude that to monitor the dynamic change of serum osmolality from time to time is of great help in lowering the incidence and mortality of hyperosmotic complications. Serum osmolality monitoring plays an important role in making fluid balance and compromizing the contradiction between dehydration and infusion as well as prevention and therapy of hyperosmotic complications, and outcome estimation as well.